Human rights groups have expressed outrage after a former Argentinian army officer accused of committing murder and forced disappearances during the 1976-83 military dictatorship was found enjoying a beach holiday in Sicily.

Reporters from la Repubblica discovered Lt Colonel Carlos Luis Malatto in a tourist village in the province of Messina, even though he is currently on trial in Rome for crimes committed in Argentina, which is also seeking his extradition.

A video posted on the newspaper’s website shows Malatto refusing to answer questions when he was confronted by reporters.

Prosecutors in Argentina have offered a 500,000 peso (£10,000) reward for the capture of Malatto, who is accused of five counts of crimes against humanity.

Writing to the court of appeal in the Argentinian state of Mendoza, prosecutors alleged that Malatto “actively participated in various detention procedures and is one of the most infamous perpetrators” of the dictatorship “for his participation in interrogations under torture”.

Malatto fled Argentina and arrived in Italy in 2011, but in 2014 Rome refused Argentina’s request to extradite him. The following year, Italy’s justice ministry approved his trial in Rome for the murders of Marie Anne Erize, a French-Argentinian model; Juan Carlos Cámpora, the rector of the University of San Juan; Angel José Alberto Carvajal, a communist party official, and Jorge Bonil, a soldier.

However Italian judges refused to put him under house arrest, leaving him free to travel – and take beach holidays.

“We asked the Italian judiciary to at least monitor Malatto’s movements, said Jorge Ithurburu, attorney for the Rome-based non-governmental organisation 24 Marzo. “We fear that Malatto may escape justice. It is sad that Italy is still today a refuge for torturers.’’

After the 1976 coup, Argentina’s military set about systematically crushing any potential opposition, and eventually murdered some 30,000 people – almost all of them unarmed non-combatants. Pregnant prisoners were kept alive just until they gave birth; some 500 babies are believed to have been given to childless military couples to raise as their own.

In 1985, barely two years after the country returned to democracy, coup leader Jorge Videla was convicted of human rights abuses and crimes against humanity.

Since then, more than 1,000 other former officers have been sentenced for the torture and extrajudicial murder of activists and political opponents and their families.

But many former officers continue to live in hiding in Europe, especially in Italy where many Argentinians have family ties. Malatto’s family originally hailed from Abruzzo and he holds an Italian passport.

Meanwhile, relatives of the military junta’s victims are still fighting for justice: on Thursday the human rights organisation Grandmothers of Plaza de Mayo announced that they had identified the 130th victim who was taken from his mother during the dictatorship.

The group said that Javier Matías Darroux Mijalchukis was a four-month old baby when he was kidnapped with his mother Elena Mijalchuk, days after his father Juan Manuel Darroux vanished. Both parents were forcibly disappeared.

Next month, a court in Rome is due to give the final verdict in the trial of 24 men for their involvement in Operation Condor, a secret programme in which the dictatorships of Argentina, Brazil, Paraguay, Uruguay, Chile, Bolivia, Peru and Ecuador conspired to kidnap and assassinate opponents in each other’s territories.

The trial focused on the disappearance of 23 Italian nationals during the 70s and 80s.

But activists warn that many of the perpetrators are growing old and may never be brought to justice. “We must act quickly,” said Ithurburu, “because the more time passes the more the witnesses of those atrocious crimes age or die’’.