Gerardi released a damaging report into wartime atrocities

Mr Arzu used parliamentary immunity to avoid testifying.

Gerardi was killed two days after releasing a report which blamed the military for 95% of the atrocities committed during the civil war which ended in 1996.

Some 150,000 people are believed to have been killed in the conflict, and more than 50,000 disappeared, but so far most of the crimes have gone unpunished.

Key testimony

Colonel Lima was sentenced along with his son, Captain Byron Lima Oliva and Jose Obdulio Villanueva, both members of the presidential guard. All three were sentenced to 30 years in jail.

Gerardi's assistant, Reverend Mario Orantes, found guilty of acting as an accomplice, was given a 20-year prison term. The bishop's cook, Margarita Lopez, was found innocent of the same charges.

The court said it based its ruling largely on the testimony of the key prosecution witness, Ruben Chanax, a homeless man who claimed he had been hired by the army officers.

Mr Chanax said he had been told to spy on Bishop Gerardi, and to alter the scene of the crime before the police arrived. He told the court he had been warned that someone would die.

Death threats

Human rights groups and church organisations held a vigil outside the court as the verdict was read amid tight security.

Two investigating judges, three key witnesses and at least one prosecutor fled Guatemala in fear of their lives.

Flor de Maria Garcia, the final investigating magistrate, said she had received death threats at every step of the process.

On the eve of the trial, which began in March, a bomb exploded outside the house of one of the three judges hearing the case.