A Seychelles government official told CNN Thursday the presence of drug traces and hypodermic needles near the corpses "would suggest that their deaths were a result of drug overdose," even though an autopsy would be performed.
Seychelles police identified the bodies found Tuesday as Jeffrey Reynolds and Mark Kennedy, both 44, and employed by Virginia-based Trident Group, a maritime security services firm. Trident Group President Tom Rothrauff said Reynolds and Kennedy were former Navy SEALs.
Police said the ship arrived in the Seychelles Sunday with a 24-man crew and was scheduled to depart Tuesday. A colleague found the bodies Tuesday, Seychelles police said.
"Based on our experience with the contractor, this is an isolated incident," Maersk said.
The shipping company said new drug tests would begin immediately and the company's shore-leave policy was under review, CNN said.
The company said Thursday the cargo ship has left the Seychelles capital of Port Victoria, the company said Thursday.
The 500-foot Maersk Alabama was the target of an attempted hijacking off east Africa in 2009, which inspired the 2013 film "Captain Phillips" with Tom Hanks in the title role.