YEREVAN (RFE/RL) — The Special Investigation Service (SIS) is looking into claims made recently by a former senior official about massive falsifications during the 1998 presidential election that allegedly gave victory to then Prime Minister Robert Kocharian, a spokesperson said on Friday.

Marina Ohanjanian said probing other assertions that former deputy defense minister Vahan Shirkhanian made in an open letter earlier this week, including that Nairi Hunanian, the leader of a group that carried out a deadly attack on the Armenian parliament in 1999, was a National Security Service (NSS) agent, is “outside the scope of the SIS’s powers.”

Meanwhile, earlier on Friday director of the NSS Artur Vanetsian neither confirmed, nor denied Shirkhanian’s claim that Hunanian was an agent, referring journalists to the SIS that he said led the relevant investigation. He also said that the entire related information will be published after a “special procedure.”

In his letter Shirkhanian, who occupied the senior Defense Ministry post in the 1990s and is now facing coup charges in a trial of a group of individuals arrested in 2015 and accused of plotting to seize power, claimed that the then head of the NSS Gorik Hakobian presented to Kocharian and military prosecutor Gagik Jhangirian “a file with the case of NSS agent Nairi Hunanian”, but that file later allegedly disappeared.

Hunanian led an attack in which then Prime Minister Vazgen Sargsian, Parliament Speaker Karen Demirchian and six other senior lawmakers and government members were killed. Hunanian and five other members of his group were convicted on charges related to the attack and sentenced to life imprisonment in 2003. Another member of the group was sentenced to 14 years in prison, but did not survive his term.

In his letter Shirkhanian also claimed that Kocharian falsified the outcome of the runoff of the 1998 presidential election with Demirchian, a former leader of Soviet Armenia who made a political comeback and reemerged as quite a popular figure less than a decade after the USSR’s collapse.

Demirchian conceded defeat and later allied himself with then powerful defense minister Sargsian. The duo went on to win parliamentary elections the following year. Their tandem remained powerful in the country for several months until the October 27, 1999 terrorist attack in which both were assassinated.

Armenian opposition groups for years alleged that despite the arrest and trial of the immediate perpetrators of the attack its real mastermind has never been revealed.

Kocharian, who served as president for two consecutive five-year terms in 1998-2008, is currently in pretrial detention on charges of overthrowing the constitutional order in connection with the 2008 post-election crackdown on the opposition during which eight demonstrators and two security officers were killed.

Kocharian denies the accusations as politically motivated.