Updated

Spain's National Court has begun hearing the trial of a former Guatemalan interior minister accused of ordering the execution of 10 prisoners in his country a decade ago.

Carlos Vielmann, who was minister from 2004 to 2007, pleaded innocent in court Tuesday.

State and private prosecutors accuse Vielmann of overseeing the summary execution of 10 inmates at two prisons between 2005 and 2006. In one case, seven died when security forces stormed the Pavon prison to quell a mutiny. Vielmann has previously said the prisoners died while resisting security forces.

Vielmann, who has Spanish nationality, could face up 40 years in jail if found guilty. The trial is expected to last a month.

He was arrested in Madrid in 2010 after a United Nations-backed commission linked him to the deaths.