Former Congress minister Mankotia, who had demanded the registration of the case against Virbhadra Singh and others, had released the CD before the Hamirpur parliamentary by-election in May 2008.

The police also sent the CD and their voice samples for voice analysis at the Chandigarh-based Central Forensic Science Laboratory.

Despite repeated attempts by IANS to contact him, Virbhadra Singh was unavailable for comment.

A five-time former chief minister, Virbhadra Singh belongs to the erstwhile royal family of Bushehr state. He is popularly known as 'Raja Saab'.

During the parliamentary elections this year, the Congress won one of the four seats in Himachal Pradesh, with Virbhadra Singh winning in Mandi by a margin of 13,000 votes.