Mr Colom has always denied playing any role in lawyer's murder
A UN investigation has cleared Guatemala's President Alvaro Colom of involvement in the murder of a prominent lawyer, Rodrigo Rosenberg.
Mr Rosenberg, who died last May, had warned in a video that he would be killed on the orders of the president.
Now UN investigator Carlos Castresana says Mr Rosenberg ordered his own assassination.
He added that the lawyer's own cousins carried it out without knowing Mr Rosenberg was the victim.
He was shot dead days after recording a video saying the president was out to kill him, and would be responsible if he were found dead.
Investigators now believe that Mr Rosenberg asked cousins of his first wife to help him contact a hitman.
He then fed information to his killers, using a second mobile phone to leave himself threatening messages.
The newspaper The Guatemala Times says he was distraught over what he claimed were murders and money-laundering by the president and his aides.
The paper adds that he may have planned his own death to topple the government.
Mr Colom has always denied any involvement in the killing.
He suggested that both the murder and the video were a reaction to his attempts to tackle organised crime.
The investigation was carried out by the UN agency known as the International Commission against Impunity in Guatemala (CICIG).
The commission was created in 2007 to tackle widespread corruption in the country.