A 27-year-old police officer who has been suspended from duty since 2013 for extortion, is being treated as the chief suspect in a murder committed in a suburb of Piraeus on Thursday.

Police arrested their fellow officer in the early hours of Friday. Investigators believe he murdered his cousin, a 30-year-old man who ran a betting agency, and that money played a role in the motive.

The 30-year-old was found stabbed to death in his home in the suburb of Kallipoli on Thursday evening by police responding to an emergency call made by neighbors.

The 27-year-old suspect was suspended from duty in February 2013 after being found guilty of extorting money from a Pakistani shopkeeper in Piraeus and threatening him with violence.

The officer was under interrogation at Athens Police Headquarters late on Friday.