Venezuelan President Hugo Chavez hopes he will soon have proof that a high-profile captive held by Colombian Marxist rebels is alive, he said on French television on Wednesday.

Chavez is mediating a possible prisoner exchange between the government of Colombian President Alvaro Uribe and the Revolutionary Armed Forces of Colombia (FARC), a guerrilla group that has waged a four-decade war against the state.

The FARC wants rebels locked in government prisons to be freed in exchange for its most high-profile captives, including French-Colombian politician Ingrid Betancourt and three U.S. contract workers held for years in jungle camps.

Chavez said he hoped to have proof Betancourt is alive by the time he visits France on Tuesday to meet French President Nicolas Sarkozy.

"I hope that I can bring with me proof that Ingrid is still alive. I don't have this proof yet, but I hope to get it before I arrive in Paris on November 20," Chavez told France 24.

Chavez's remarks were broadcast before the full interview, which is due to be aired on Thursday.

"I believe I can bring Sarkozy some good news," he said.

"But I'll also have some demands because he (Sarkozy) can help find an agreement between the Colombian government of President Uribe and the FARC leaders, which he wants to see happen."