A former army captain convicted of murdering a Guatemalan bishop has been killed in a prison riot in which 13 people died.

The riot that killed Byron Lima Oliva, who was serving 20 years for the murder of Bishop Juan Gerardi in 1998, took place in Pavoncito, a prison 18 miles (30 km) from the capital, Guatemala City.

The killing of the bishop was one of the most notorious crimes in recent Guatemalan history. Gerardi was a human rights campaigner who was active in working for the indigenous Mayan people of his country. Among other achievements, he secured government recognition for indigenous languages and permission for radio stations to broadcast in them. He was appointed to the government's National Reconciliation Commission after the country's long-running civil war, which ended in 1996.

As Bishop of Quiché he was confronted with the deaths of hundreds of Christians, mainly of Mayan origin, at the hands of the army.

Gerardi was murdered two days after he presented testimony about the atrocities to the Recovery of Historical Memory Project, sponsored by the Catholic Church.

Lima, who was jailed for his murder with two other army officers, was infamous for heading a criminal network inside and outside the prison system, running illicit businesses including food stalls and a transportation enterprise for relatives of inmates from his prison cell.

Additional reporting by Reuters.