American diplomats have visited a US citizen jailed in Venezuela whom President Hugo Chavez suspects of being a "mercenary" sent to join a plot against him, the US Embassy says.
"We have been granted consular access to a detainee. We were just told this morning 'he is ready to see you now'," an Embassy official told Reuters.
Implying a US-backed, anti-government plot was afoot less than two months before a presidential election, Chavez announced the detention last week, saying an American citizen of Hispanic descent had been found entering illegally from Colombia.
He sought to destroy some co-ordinates in a notebook at the time of his arrest, and has resisted interrogation beyond identifying himself as a former US Marine, Chavez has said.
Foes have scoffed at Chavez's statements, saying it is typical of him to invent tales of foreign-inspired aggression against him at election time. Washington has given no detailed information on the case, beyond pressing for consular access.
After the visit to the man, the US embassy said it could give no further details "due to privacy considerations".
"The embassy will continue to communicate with the government of Venezuela on the case and seek further access when appropriate," it said.
Though there have been constant flare-ups between Washington and Caracas since the ferociously "anti-imperialist" Chavez took power in 1999, the latest incident is not mushrooming into a major dispute, even though Chavez said the man was probably a "mercenary" linked to alleged opposition destabilisation plans.
Privately, Western diplomats in Caracas say the roots of the incident were probably in neighbouring Colombia, not Venezuela, with the American apparently fleeing some sort of problem there.
Chavez, 58, is fighting for another six-year term at the October 7 vote, but faces a vigorous campaign from a united opposition candidate, Henrique Capriles. Chavez has declared himself fully recovered from two rounds of cancer surgery in the last year.
US President Barack Obama, also seeking re-election in November, has kept a low-profile line on Venezuela this year despite calls from his rival, Mitt Romney, to take a tougher stance against Washington's fiercest critic in the region.