(CNN) -- Traces of narcotics and hypodermic needles found with the bodies of two American security officers on the container ship Maersk Alabama suggested the deaths resulted from drug overdoses, a Seychelles government official told CNN on Thursday.
Seychelles police identified the bodies found Tuesday as Jeffrey Reynolds and Mark Kennedy, both 44. They worked for Trident Group, a Virginia-based maritime security services firm, and Trident Group President Tom Rothrauff said both were former Navy SEALs.
"It's bizarre. Of course, it's a shock. They're all great guys," Rothrauff said. "I'm absolutely clueless as to what happened."
Police said an autopsy would be carried out later this week. But the Seychelles government official, who spoke on condition of not being identified, said the presence of drug traces and paraphernalia "would suggest that their deaths were a result of drug overdose."
The 500-foot Maersk Alabama was the target of an attempted hijacking in the pirate-infested waters off east Africa in 2009 -- an incident that inspired the 2013 film "Captain Phillips." The shipping giant Maersk, which hired the Trident Group to guard its ships, said Thursday that Trident would be conducting random drug tests of its employees.
"Based on our experience with the contractor, this is an isolated incident," Maersk said. But it said new drug tests would start immediately and the company's shore-leave policy was under review. The Maersk Alabama has since left the Seychelles capital of Port Victoria, the company said Thursday.
Police said the ship arrived in the Seychelles, an archipelago in the Indian Ocean, on Sunday with a 24-man crew and had been expected to leave Tuesday. The bodies were found by a colleague who had gone to check in on one of the men in a cabin at about 4:30 p.m. Tuesday, Seychelles police said.
Lt. Cmdr. Jamie Frederick, a U.S. Coast Guard spokesman, said the service was investigating the deaths, as required by American law. But he said the deaths "do not appear to be criminal in nature, related to vessel operations, the material condition of the ship or their duties as security personnel."
In April 2009, four armed pirates attempted to hijack the Maersk Alabama 380 miles off the coast of Somalia. After the crew sank the pirates' vessel and foiled their efforts to take control of the container ship, the pirates took the ship's captain, Richard Phillips, hostage on a lifeboat.
The incident ended three days later when Navy sharpshooters killed three of the pirates and captured the fourth. Phillips was unharmed.
The ship was attacked by pirates again later that year, but armed security personnel fought them off. Another attempt by pirates to board the ship, in March 2011, was thwarted when security personnel fired warning shots.