Hopes of future oil prosperity have given a lift to Ghana's presidential election race, but drug trafficking threatens to spoil the West African country's image with the stain of corruption.

During the heated election contest, to be decided in a December 28 run-off, lurid headlines in the partisan press accused both main rival parties of collusion in trafficking or of using drug dollars to win votes.

Hard evidence was lacking, but the allegations are indicative of Ghana's failure to tackle an illicit trade experts fear is turning West Africa into a "Coke Coast" and of corruption that threatens to cloud a bright future.

After years of military rule and economic instability, Ghana has been seen as a success story since President John Kufor was elected in 2000, attracting foreign donors and investors eager for a safe haven in a restive region.

Yet tonnes of cocaine vanishing from police surveillance, a parliamentarian jailed in the United States for trafficking heroin, and the sabotage of efforts to combat smuggling or graft are more reminiscent of the region's failed or failing states.

"I think it's an extremely serious threat," said Patrick Smith, editor of newsletter Africa Confidential.

"It's not just the transhipment, it's the criminalization of the economy and of institutions. There is growing hard drug use among Ghanaians. They are all mutually reinforcing factors, and yet the government has not come down hard on them," Smith said.

Yao Gede, a lecturer in international relations at the University of Ghana, said the record of Kufuor's administration in attracting investment and extending health and education services was undermined by widespread suspicions of graft.

"There is that perception of corruption in the country, there is the belief that resources have not been shared equitably," he said.

Increased investment in Ghana, encouraged by the startup of offshore oil production scheduled for late 2010, raises the stakes for both the criminal networks and those fighting them.

"We hear of ... people being approached with huge cash offers to sell their houses to Colombians and Venezuelans, and it's clearly (money) laundering," said Smith.

BUYING INFLUENCE

Nigerian gangs began smuggling heroin through the country in the 1980s, said Antonio Mazzitelli, regional head of the U.N. Office on Drugs and Crime. The U.S. Drug Enforcement Agency describes Ghana as a common transit country for heroin.

Eric Amoateng, a member of parliament for Kufuor's ruling New Patriotic Party (NPP), was arrested in 2005 for smuggling 136 pounds (62 kg) of heroin into New York's Newark airport.

Amoateng was jailed last year by a U.S. court after quitting his seat, but enjoyed significant support from parliamentarians and constituents who regarded him as a philanthropist.

"There is a perception on the ground that it has got worse under the current regime ... That is one of the major issues of the campaign," said Sebastian Spio-Garbrah, an analyst at U.S. risk consultancy Eurasia Group.

The NPP's chosen successor to Kufuor, Nana Akufo-Addo, is counting on the party's record after eight years in power to defeat opposition chief John Atta Mills, of the National Democratic Congress (NDC) in next Sunday's run-off.

Neither party's record is unblemished. Under former coup-leader turned president Jerry Rawlings, the NDC ruled Ghana throughout much of the 1980s and 1990s when heroin smuggling networks became entrenched.

DISAPPEARING DRUGS

In recent years, cocaine trafficking has been spread across West Africa by rich, well-armed Latin American gangs who have used the impoverished region as a transhipment route to smuggle drugs into Europe.

"Although Ghana is mainly a transit point for drugs, there is an increasingly organized framework within which these transactions take place," Kwesi Aning, head of conflict prevention at the Kofi Annan International Peacekeeping Training Center in Ghana, wrote in a 2007 report on criminal networks.

The sums involved can be devastating for law enforcement in a country where anti-drugs officers are paid $90 a month.

In 2006, around 2 tonnes of cocaine smuggled into Ghana on board a merchant ship simply vanished after it was seized by police. The case rocked the establishment.

Operation Westbridge, a British-backed program, has helped counter trafficking by "mules" who carry or swallow small bags of cocaine to smuggle it on flights to Europe. But Ghana's land and sea borders remain vulnerable to bigger shipments.

"Judging by the number of scandals ... traffickers and drug money have infiltrated law enforcement agencies at all levels," UNODC's Mazzitelli said.

"It's certainly a threat, and drug money -- criminal money -- can become an obstacle, or a competitor, to licit investment. Ghana wishes to be a financial hub in West Africa, and it has all the qualities for becoming it, but certainly it has to protect its banking system," he said.