LAGOS, Nigeria — The woman blended effortlessly with the hundreds of travelers negotiating the maze of security checkpoints, tax collectors, passport stampers and bribe-takers at Murtala Muhammed Airport.
She was a slender, 25-year-old Nigerian with braided hair, dressed in light cotton trousers and a T-shirt. She held a ticket for the late-night flight to Amsterdam. It was her container of palm oil, a staple of Nigerian cooking, that raised the security officer's suspicions.
"You're taking this to Europe?" the officer asked.
"It's for my boyfriend," she replied. "He's never had a meal cooked in palm oil."
Skeptical Nigerian agents heated the gallon-sized jug of solidified oil and, lo and behold, a plastic bag of heroin bobbed to the surface.
But for every smuggler the Nigerians catch, there are hundreds, probably thousands, who walk unchallenged through the gaping airport security net.
Foreign drug agents based here estimate that every plane, every night, holds at least one passenger smuggling heroin or cocaine.
In fact, lax security at the airport and a culture of corruption have made this city of 8 million people one of the busiest drug transit points in the world, international experts say.
Heroin arrives here in bulk from the Far East, often via Lebanon or Pakistan; cocaine arrives from South America. Then nearly all of it is exported, pound by pound, on the backs, in the luggage and, increasingly, in the bellies of Nigerian couriers.
"Nigeria is a major, major heroin trafficking and transit point," said Roger Guevara, a spokesman for the U.S. Drug Enforcement Administration in Washington. "I hate to say anything derogatory about Nigerians, but let's just say they're very good at what they do."
In recent years, almost 80% of the heroin seized at John F. Kennedy International Airport in New York has, at one point or another, passed through Lagos, DEA and U.S. Customs officials report.
Half of the heroin seized in the United States is being carried by Nigerians or other West Africans. Just a few weeks ago, agents busted a Nigerian drug smuggling ring based in San Francisco.
"Nigeria is a safe haven for individuals, drug barons and drug dealers," said a Western drug expert with three years' experience in Nigeria. "The reason? C-o-r-r-u-p-t-i-o-n."
Like other foreign drug agents here, he spoke on condition of anonymity. In the last year, one American drug agent and one Italian agent have been shot in ambushes. No arrests have been made.
The battle by American and European authorities to close the Lagos loophole in the world drug network has been uphill.
The American government, citing poor security, banned all direct flights between Lagos and the United States last August. In response, the Nigerians installed their first airport X-ray machine.
But American officials say security remains poor.
A review of the flight ban is expected in March. If the airport isn't recertified, the United States is legally bound to suspend all non-humanitarian aid to Nigeria.
Shutting down direct flights to the United States has only changed the path of the drug highway.
Now, American experts say, more Nigerians are smuggling drugs into the United States through European airports, overland from Canada and Mexico, and on flights from the Caribbean.
The Nigerian government's anti-drug efforts are coordinated by the 4-year-old National Drug Law Enforcement Agency, housed in a collection of dilapidated, unmarked buildings in a thicket of palm trees on Lagos' Victoria Island. Of its 2,000 agents, 200 are assigned to the 24-hour airport detail.
Nigeria's drug agency is sharply criticized by foreign diplomats as incompetent and corrupt.
The agency is especially plagued by cases of confiscated drugs that mysteriously disappear. Four agents were sent to jail last year for tampering with evidence.
Nigerian authorities made 279 drug arrests last year and confiscated 135 pounds of cocaine and 80 pounds of heroin.
But much more got through.
Authorities at London's Heathrow Airport arrested nearly one Nigerian a day last year. And those are just the couriers.
Nigerian agents have been unable or unwilling to arrest any major drug barons, many of whom receive friendly escorts through airport checkpoints and flash their enormous wealth on the streets of Lagos.
"The Nigerian authorities are doing exactly nothing, except collecting money from the drug barons," a U.S. drug agent complained. "It's a disgrace."
At one border post two months ago, authorities had to fire tear gas to break up a dispute between Nigerian customs agents and drug enforcement agents.
The fight, it turned out, was over who could extort money from importers.
Then, last month, a 560-pound shipment of heroin from Thailand was seized by Nigerian agents, acting on a tip from British intelligence.
Within days, some of the heroin was reported missing.