The US Navy has initiated an investigation over cash that went missing during a rescue operation to save a ship’s captain from Somali pirates.

The captain of the Maersk Alabama, Richard Phillips was rescued by US Special Forces in April after being kidnapped by pirates.

Navy snipers onboard the USS Bainbridge rushed to the scene, killing three pirates after the US administration sanctioned the mission following a five-day stand off.

An alleged amount of around $30,000 disappeared from the ship’s safe during the hijacking.