It was not out of shame. Since becoming Nigeria's top food and drug regulator in 2001, his mother had broken the back of an illicit trade that had flooded Nigeria with fake medicines. She had taken on importers, distributors and an array of officials willing to risk Nigerian lives for a bribe.

But her son feared what might happen should her enemies track him down. So he told everyone that his mother was an aunt.

"That caused me a lot of pain," Mrs. Akunyili said. "He denied I was his mother. But the young boy saw the danger."

In Nigeria, even children understand corruption's menace. Increasingly, so do the donors that have poured more than $300 billion into African nations since 1980 - and watched too much of it vanish into a sinkhole of fraud, malfeasance and waste.

Now the efforts of reformers like Mrs. Akunyili are being scrutinized at meetings where donor countries consider aid to Africa, as leaders of the Group of 8 industrialized nations will do this week at Gleneagles, Scotland.

The summit meeting has been billed as a turning point for Africa, where the billions have begun to flow again. Foreign aid to the continent reached a 17-year low in 1999, but in May, the richest nations agreed to write off $40 billion in loans owed by the world's 18 poorest countries, all but four of them in Africa.

No African nation points up the challenge quite like Nigeria, a country that is both hampered by corruption and trying to control it. Awash in oil and gas that has flooded its treasury with $300 billion in the past 20 to 30 years, Nigeria remains utterly destitute, in no small part because of waste and graft. Officials like Mrs. Akunyili have scored some victories, but few corrupt officials have been convicted and millions of aid dollars still go astray. So donors are confronted with the question in Nigeria, as in much of Africa, of how much improvement is enough.

Corruption has not only robbed Africa of money to help lift some of the world's poorest people out of poverty. Around the world, it has also stalled economic development and tarnishes people's faith in government and, often, democracy itself.

The host of the summit meeting, Prime Minister Tony Blair of Britain, wants to double global aid to Africa to $50 billion a year by 2010. Although he appears unlikely to reach that goal, aid is clearly on the rise: both the European Union and the United States propose to double their assistance during that period because African nations are lagging further behind their industrialized counterparts and richer nations fear that failed states can become breeding grounds for terrorism.

And while the United States devotes less of its wealth to foreign aid than the other nations at the talks, it has already tripled aid to Africa since 2000.

But this new giving is increasingly dependent on proof that its recipients are controlling corruption and governing wisely. Mr. Blair's Commission for Africa, which he established last year, concluded in a report in March that "without progress in governance," including tackling corruption, "all other reforms will have limited impact."

The United States has been even more blunt: "Countries like ours are not going to want to give aid to countries that are corrupt or don't hold true to democratic principles," President Bush said last month after meeting with South Africa's president, Thabo Mbeki.

That this tough-love approach is rapidly becoming conventional wisdom is one measure of the turnabout in the approach to foreign aid since the cold war, when both sides showered cash on African allies with scant regard to how much was stolen or wasted.

Still, how high to set the good-governance bar - and deciding who clears it - is in the eye of the donor. Jeffrey D. Sachs, a Columbia University economist who wrote a December 2004 report to the United Nations on fighting poverty, said that at least two dozen poor nations, many in Africa, are well-enough run to manage a rapid infusion of aid. The Bush administration's Millennium Challenge Account, set up last year to promote economic growth in poor countries, says just seven impoverished African nations qualify, with another six on the verge.

There is ample fodder for pessimists and optimists alike. On the positive side, a growing number of African nations are edging away from crime and autocracy toward democracy and openness. Ghana, which marked its first peaceful democratic transfer of power in 2000, is often cited as a regional model of reform. Tanzania's president, Benjamin Mkapa, claims that an anticorruption campaign has led to a four-fold increase in government revenue in the decade since the nation's first multiparty elections. Zambia is trying its former president, Frederick Chiluba, for stealing $488,000 in state funds - even though he handpicked the successor whose government has charged him.

Crucial Role for Donors

Yet a May study by the World Bank found that between 1996 and 2004, the quality of governance deteriorated in as many African countries as it improved.

Kenya is a painful illustration: a government ushered in two years ago on an anticorruption platform saw its widely respected anticorruption czar quit in frustration in February, apparently because his work was thwarted. The United States and Germany quickly withdrew nearly $10 million in aid.

Whether the new wave of African aid avoids the pitfalls of the past depends not just on its recipients, development specialists say, but also on the donors, who have often pushed poorly devised projects, refused to coordinate their efforts or demands with one another and failed to monitor the impact of their largesse.

Foreign aid must be tied to teaching poor nations how to build accountability into their governments, development specialists contend. In some countries, it is not even clear whether the executive branch or the parliament controls the budget, said Steven Radelet, a senior fellow for the Washington-based Center for Global Development. He warned, however, that such improvements typically require generations to take root.

Nigeria is one of many nations where aid has been wasted, or simply stolen. Lagos, home to 15 million of Nigeria's 137 million people, is among the world's most troubled cities, replete with open sewers, foul tap water, garbage-strewn roads and traffic that perennially seems at a standstill.

Not including World Bank loans, which in some years totaled as much as $1 billion, Nigeria took in $3.5 billion in aid from 1980 to 2000. That was a few hundred million less than Sani Abacha has been accused in news reports of stealing in the five years he ruled Nigeria as a military dictator before his death in 1998. Dismayed, donors pulled back or out. Aid in 1999 totaled half the 1990 level.

Later audits disclosed scores of botched projects financed with hundreds of millions of dollars in international loans. Nigeria's government never even cleared the site for an $18 million construction project. Millions were spent on paper mills that never produced any paper. Eighteen projects costing $836 million were never completed; another 44 either never operated or were quickly shut down, the Nigerian Finance Ministry reported. Of 20 other projects started between 1985 and 1992, more than half had little impact or were unsustainable, the World Bank concluded.

But with the 1999 election of Olusegun Obasanjo, donors' enthusiasm reawakened. Mr. Obasanjo's anticorruption credentials seemed impeccable: he helped found Transparency International, an anticorruption group, and strongly backed a program by African leaders to review each other's adherence to democracy and good governance. Since his election, aid to Nigeria has doubled.

Yet Mr. Obasanjo's first term ended with little progress. "He wanted a second term, and he believed that if he took the anticorruption war too seriously, they would make sure he didn't get a second term," Jibirin Ibrahim, a political scientist and director of Global Rights, a Nigerian pro-democracy group, said of corrupt officials. "Which was a strategic mistake, because these people were able to further entrench themselves in the system."

Now, with two years left in his second term, Mr. Obasanjo's crusade appears to have regained steam. In recent months, his education minister was arrested for bribing legislators. His housing minister was fired for selling government property at cut-rate prices. And the police inspector general was led away in handcuffs on charges of money-laundering.

Some early initiatives also appear to be bearing fruit. Oby Ezekwesili, a senior aide to the president, said the government had saved $1.3 billion since the start of 2003 by insisting on competitive bidding in awarding contracts.

But the list of unfinished business is formidable, including removing the constitutional guarantee of immunity for the nation's most senior officials and opening government records to the public.

Bribes and Bottlenecks

Other obstacles remain.

Although Mr. Obasanjo's first act as president was to establish an anticorruption commission, the office has secured just two corruption-related convictions among the 85 people it has charged in its five years.

Mustapha Akanbi, a retired judge who heads the commission, said he suspected that some judges have been paid off to toss out cases.

Government officials have also resisted change.

After investigators uncovered bribes to a hospital medical director, Mr. Akanbi said, the health minister refused to fire him until Mr. Akanbi complained personally to the president. "Every single step you take, there are bottlenecks," said Mike Sowe, the commission's spokesman.

When Mrs. Akunyili took over as director of Nigeria's National Agency for Food and Drug Administration four years ago, perhaps four-fifths of her agency's regulators were corrupt, she said in a recent interview. Even worse, two in three drugs sold publicly were either unregistered or unsafe for consumers.

Mrs. Akunyili knew the danger well: her sister, Vivian, a diabetic, died in 1988 after what she believes was an injection of fake insulin.

Every few weeks, Mrs. Akunyili's agency made a show of burning heaps of fake drugs collected at airports, seaports, illegal factories and distributing houses. A spot check last year showed the impact: only one in eight drugs was unregistered. Major pharmaceutical companies have now returned to Nigeria, and other African nations have agreed to lift their bans on Nigeria's drugs.

Doctors were among the most grateful. "We know the drugs are real now, because the patients don't come back with the same symptoms," said Sister Josephine Ngama, a senior doctor at Ancilla Catholic Hospital on the outskirts of Lagos. "People had been trading in these fake drugs for years."

Honored and Imperiled

Mrs. Akunyili has been showered with awards, but her family is pressing her to quit.

Seven months after she took office, 10 armed men invaded her home, leaving only after learning that she was not there.

In December 2003, armed gunmen attacked her car. A driver in a nearby bus was killed. One bullet went through Mrs. Akunyili's blue headdress, grazing her skull.

"It's like a war," she said. "They are fighting back."

Reformers like Mr. Akunyili stand out partly because they are so rare.

"Hopefully, they are going to do enough good that people are going to be attracted to them," said Victoria Kwakwa, the lead economist for the World Bank here. "It is going to have to start with small groups, because you don't have the base. If you did, you wouldn't have gotten to this point to begin with."