Jailed radical preacher and Khadoor Sahib MP Amritpal Singh's father Tarsem Singh on Saturday questioned the police's claim of Amritpal's involvement in the murder of a Sikh activist and demanded a probe by a sitting judge of the Punjab and Haryana High Court.

Tarsem Singh's statement came a day after Punjab Police chief Gaurav Yadav claimed that Sikh activist Gurpreet Singh Hari Nau was killed at the behest of Amritpal Singh, who is lodged in Dibrugarh jail in Assam under the stringent National Security Act.

The police claimed to have solved the murder case with the arrest of three members of the gang led by Arshdeep Singh Dalla, a designated terrorist and alleged mastermind in this case.

Gurpreet Singh Hari Nau alias Bhodi was shot dead on October 9 while returning home from the village gurdwara on his motorcycle.

Tarsem Singh said his son has been in the high-security jail in Assam for over a year now as he contested the police's claim of Amritpal's involvement in the murder.

"We want a sitting judge of the high court to probe the murder case," he told reporters.

He alleged that attempts were being made to indulge in "character assassination" of Amritpal as the "system" was unable to "digest" his victory in the Lok Sabha polls from the Khadoor Sahib constituency.

Director General of Police Yadav on Friday said that evidence had come on record indicating the role of Amritpal Singh of Waris Punjab De (WPD) in the murder conspiracy.

Amritpal Singh, who heads the 'Waris Punjab De' outfit and has styled himself after slain Khalistani militant Jarnail Singh Bhindranwale, was arrested during a crackdown in April last year and jailed along with nine of his associates under the NSA.

He contested the recent Lok Sabha election while in jail.

Except for the headline, this story has not been edited by The Telegraph Online staff and has been published from a syndicated feed.