Colombian officials say rebels who had announced plans to release three hostages Sunday have released only one so far.
Authorities say the Revolutionary Armed Forces of Colombia, or FARC, released police officer Carlos Ocampo, who was kidnapped in December.
However, the other two hostages - police Major Guillermo Solorzano and Army Corporal Salin Sanmiguel - remain in captivity.
Colombia says the rebels provided false coordinates for the location of the hostages, placing them in Tolima state when the men were instead in Cauca state.
Eduardo Pizarro, the government representative in the hostage negotiations, said providing the wrong information was "scandalous."
However, there is some indication bad weather may have interfered with the transfer plans.
Solorzano was captured in June 2007, while Sanmiguel was kidnapped in May 2008.
Last week, FARC released three hostages.
FARC has been at war with the Colombian government since the 1960s. The rebel group has been designated as a terrorist organization by Colombia, the United States and the European Union.
While most of FARC's funding comes from cocaine trafficking and extortion, the leftist rebels are believed to be holding around 20 police and soldiers, and an unknown number of civilians, for ransom or political leverage.