KITTERY (AP) – Investigators are trying to determine what caused the death of a 44-year-old commander of a Coast Guard cutter whose body was found in his cabin by crew members while the vessel was docked at the Portsmouth Naval Shipyard.

The body of Cmdr. Keith Willis, a 20-year veteran of the Coast Guard, was discovered on board the Tahoma around 10 a.m. Sunday.

A 12-member honor guard accompanied the body ashore Sunday evening. The Maine medical examiner’s office in Augusta will conduct an autopsy on Willis, said Lt. Robert Wyman, spokesman at the Coast Guard’s Atlantic Area headquarters in Portsmouth, Va.

Wyman said he had no information on whether there was any reason to believe the death was suspicious.

Willis, a native of Frisco, N.C., was a Coast Guard Academy graduate who took command of the 270-foot Tahoma in 2007.

The Tahoma, with a crew of 100, had returned to its homeport at the Kittery yard Jan. 28 after a deployment off New England. It had conducted various missions for law enforcement and marine safety.

The Naval Criminal Investigative Service and the Coast Guard Investigative Service are investigating.