Police said on Saturday that they had appointed a special team to investigate the "alleged suicide" of a retired army officer who was found hanging at home with a suicide note claiming responsibility for the murder of the former Sunday Leader Editor Lasantha Wickrematunge.

The body of the retired officer was found at his home in Kegalle with a suicide note stating that he was responsible for the assassination of journalist Lasantha Wickrematunge and asked for the release of the army intelligence officer who is currently under arrest over the murder.

Police said they were investigating if there was any truth to his letter while many on social media raised questions if the alleged suicide was a cover up to protect Wickremetunga's actual killers.

"We have begun investigations to see if there is any truth to this," a police official who wish to remain unnamed told Xinhua earlier.

Wickremetunga, who was the editor of the local Sunday Leader newspaper, was shot dead while driving to work in January 2009 by a group of unidentified men in a high security zone in broad daylight.

Last month, authorities exhumed Wickrematunga's remains to conduct a fresh autopsy after fears that forensic evidence may have been tampered with or deliberately falsified to mislead the investigation.