london • Doubt was cast yesterday on the apparently daring rescue that won former Colombian hostage Ingrid Betancourt her freedom.

The Swiss radio station RSR broadcast a report questioning the official version of the operation to free Betancourt and 14 other hostages - saying that money, not cunning, had clinched their freedom.

According to Bogota, the hostages were freed in an elaborate ruse by Colombian intelligence agents who had infiltrated the FARC rebels holding them.

But RSR said the 15 hostages "were in reality ransomed for a high price, and the whole operation afterwards was a set-up". Citing a source "close to the events, reliable and tested many times in recent years", it said that the United States — which had three citizens among those freed — was behind the deal and put the price at $20 million.

The Colombian Foreign Ministry furiously denied the allegations, with a spokesman calling them "completely false." He added: "They are lies".

General Freddy Padilla, head of the Colombian military, categorically denied they had paid "a single peso" to FARC. "As the General Commander of the Armed Forces and on my military honour, I deny that the Colombian government has paid a single peso, a single cent," he said.

Betancourt also cast doubt on the claims. "Based on what I was able to see in this rescue operation, because of the intensity, I don't think they could have fooled me," she said. "I don't think that anyone was acting. The situation was too intense."