* President has denied links to drugs smuggling
* West African state a cocaine transhipment hub
* U.S. prosecutors indict former Bissau navy chief, others
Guinea-Bissau's caretaker president may have cooperated with the planners of a doomed cocaine-and-weapons smuggling scheme meant to arm Colombian rebels, according to U.S. court filings reviewed by Reuters on Monday.
The documents cast a shadow on international efforts to restore order in the tiny West African state, which has suffered a string of coups since 1974 independence and which has since become a transhipment hub for narcotics bound for Europe.
U.S. prosecutors filed indictments against Guinea-Bissau's former navy chief, Jose Americo Bubo Na Tchuto, and six other men late last week after trapping some of them in a daring sting operation off its Atlantic coast.
According to the indictments, the men planned to bring 4,000 kg of Colombian cocaine to Guinea Bissau inside a shipment of military uniforms and then smuggle weapons, including surface-to-air missiles, back to Colombia's FARC rebels for use against American anti-drugs forces.
The filings state that one of the chief conspirators in the plan, described only as a "high-level official in the Guinea Bissau Military", told undercover agents in July he would discuss the plot with President Manuel Serifo Nhamadjo.
"The day after tomorrow, I'll talk to the President of the Republic," he is quoted as saying in the indictment, filed in New York's Southern District Court on Friday and since made public.
Two other suspects told undercover agents at a meeting in Bissau in September they would speak with the "President and the Prime Minister" about the deal, according to the documents.
"Guinea Bissau government officials would, as a fee, expect 13 percent of the cocaine," a separate unnamed suspect told the undercover agents, according to the documents.
A spokesman for Nhamadjo denied Nhamadjo had any knowledge of the plot, adding: "None of this is true. It makes no sense."
He said Nhamadjo was in Germany for medical treatment but was due to return later this week.
Nhamadjo was named transitional president in Guinea Bissau in May in a deal struck between West African regional leaders and the military commanders who seized power in a coup a month earlier, derailing elections.
The European Union and the CPLP grouping of Portuguese-speaking nations have refused to recognise his administration, claiming he remains under the influence of military leaders with links to the drugs trade.
Nhamadjo has denied the claims and has urged international support and funding for elections.
Na Tchuto's arrest by U.S. drugs agents has raised fears of an outburst of violence between Guinea-Bissau's rival military factions, who have repeatedly clashed in what observers suspect is a struggle for control of the drugs trade.
Na Tchuto has been involved in several failed coups in the former Portuguese colony and was one of two Bissau-Guineans designated as drug kingpins by the U.S. government in 2010.
Other people indicted include Colombian nationals Rafael Antonio Garavito-Garcia and Gustavo Perez-Garcia - both suspected narco-traffickers arrested in Colombia on Interpol warrants.
Guinea-Bissau is rich in natural resources - including minerals, cashews and some of the world's best fisheries - but political instability has hindered investment and kept most of its 1.6 million people mired in poverty.