Armenian National Security Service director Artur Vanetsian said on September 11 that the Prosecutor-General's Office has opened a criminal case into the wiretapping of telephone conversations between the chiefs of the National Security Service and the Special Investigation Service in which they discussed an ongoing investigation into the 2008 “Marti mek” (“March First”) post-election violence.

Secretly recorded audio of late July conversations between Vanetsian and Special Investigation Service head Sasun Khachatrian was leaked to the media and published by several news websites.

The two officials are heard discussing the case against ex-president Robert Kocharyan, who has been charged over his alleged involvement in the violence a decade ago in Yerevan in which 10 people, including two police officers, were killed.

Kocharyan has denied the charges. He has claimed the country's new government, elected after a spring “people’s revolution”, has launched a "vendetta" against him. Moscow, which has military bases in Armenia, has lately been making its dissatisfaction clear over the pursuit of figures among the dislodged former ruling establishment of its ally.

In comments on claims that his government had broken its promise not to interfere in the work of the judiciary, Prime Minister Nikol Pashinian condemned the wiretapping and the leak. He denied giving instructions to the judiciary.

"The case of March 1, 2008 must be disclosed, the murderers must be brought to justice," Pashinian said in a live Facebook broadcast.

At a rally in Yerevan later in the day, he described the wiretapping as a "conspiracy and crime against Armenia's statehood", RFE/RL reported.

The prime minister also reportedly said that he had instructed law enforcement agencies to "find those who organised the conspiracy within the shortest possible period of time and hold them accountable in the strictest terms".

Khachatrian said that investigators had proof that special army units "fully participated" in the 2008 crackdown.

Armenian leaders had "turned soldiers into mercenaries and used them against the people," he added.