Colombian president Juan Manuel Santos said the top leader of the leftist Revolutionary Armed Forces of Colombia narrowly escaped an attack on his camp by the country's armed forces.
Mr Santos said Alfonso Cano fled the camp "in the space of 12 hours, no more" before the raid, leaving behind his clothes, half his belongings and two dogs that normally accompany him.
Mr Santos told a news conference that it is the third time they have almost captured Mr Cano.
Colombia's president said the raid took place on Thursday in a rural region between the provinces of Huila and Cauca. It came after officials received a tip from within the rebel group.
Farc has been hit hard in recent years by Colombia's US-backed military.