The Red Cross said Monday there was no operation underway to free an ex-lawmaker whose captivity by the Colombian rebel group ELN is holding up peace talks with the guerrillas.

"There is no operation going on right now," a source at the International Committee of the Red Cross told AFP.

The declaration contradicted a statement by a Colombia government official last week that the ICRC was involved, with the Catholic Church, in a process to secure the freedom of the former congressman, Odin Sanchez, who was seized in April.

The ICRC is usually the go-between in hostage handovers involving rebel groups in Colombia.

The organization declined to make further comments on its role in a possible future handover of Sanchez beyond confirming it was "ready to facilitate any operation of a humanitarian nature."

Colombia's government has struck a historic peace deal with the country's biggest rebel group, the FARC, but its solidity is uncertain after voters rejected it in an October 2 referendum.

Efforts to hammer out a similar agreement with the smaller ELN have foundered over the issue of Sanchez's captivity.

Publicly announced talks were meant to have started last Thursday in the Ecuadorian capital Quito, but the government postponed them because Sanchez had not been freed.

But ELN negotiator Pablo Beltran said the group had not promised to release Sanchez before the dialogue was launched.

Colombia is seeking to put an end to a half-century of violence that has seen more than 260,000 people killed by leftwing rebels, paramilitaries and security forces.