Image caption Marine Sgt Brian LaLoup is believed to have killed himself at the American embassy in Athens

The parents of a dead US Marine whose body was returned from Greece missing its heart are suing the US Department of Defense and the Greek government.

Craig and Beverly LaLoup say they experienced emotional distress when Sgt Brian LaLoup was "illegally autopsied" overseas.

Sgt LaLoup is believed to have killed himself at the US embassy in Athens in August 2012.

The Greek embassy in Washington said his heart was removed for testing.

According to the complaint filed in federal court in the Eastern District of Pennsylvania, Sgt LaLoup, 21, attended a party at the US embassy in Athens on 12 August 2012 and told a fellow marine he was contemplating taking his own life.

His comments were later reported to a supervisor who, the LaLoups claim, offered Sgt LaLoup drinks instead of offering proper medical treatment under military protocol.

Wrong heart sent

Once intoxicated, Sgt LaLoup was allowed access to the embassy's weapons room, where he shot himself in the head, the parents say.

His body was transported to a local hospital and left unattended, where it underwent a post-mortem and his heart was removed by Greek medical staff, the complaint alleges.

The heart was later found to be missing during a second autopsy by US military officials in Dover, Delaware, on 22 August 2012, the complaint adds.

The LaLoups say they were not informed their son's heart was missing until two weeks after he was buried in the US.

They also say they were later given a heart that was not his.

"This is his heart. This is his soul. This is what made Brian who he is," Ms LaLoup told the Associated Press news agency.

The LaLoup family is seeking damages for emotional distress, rather than wrongful death for which the US government is typically immune.

A spokesman for the Greek embassy in Washington DC said Sgt LaLoup's heart was withheld for toxicology tests, the AP reported.