Petty Officer 1st Class Russell Matthews is seen in this undated picture from the U.S. Coast Guard (U.S. COAST GUARD VIA KGMB-TV)
HONOLULU (CBS NEWS) -- After disappearing three months ago Coast Guard Petty Officer 1st Class Russell Matthews suddenly showed up at his home Sunday night, CBS Honolulu affiliate KGMB-TV reports.
An investigation is under way to figure out where Matthews has been and what he's been doing. Matthews, 36, was being investigated for illegal drug use when he disappeared.
Early last October his car and slippers were found at the out-of-the-way area of Kaena Point. His hat was in the water. The Coast Guard searched 10,000 square miles during two days, but there was no sign of him.
Three months later Honolulu Police say he appeared at his wife's home Sunday night. He was incoherent, and officers took him to Castle Medical Center in Kailua. The next morning he called his Coast Guard commanders and told them he was in fact alive.
"We don't know where he's been the past few months. There is an ongoing investigation that is being conducted by the Coast Guard Investigative Service," Chief Warrant Officer Gene Maestas said.
Matthews was not hurt however he was transferred to Tripler Army Medical Center for a medical evaluation.
Maestas confirmed Matthews was being investigated by the Coast Guard for using marijuana at the time of his disappearance.
"If a Coast Guard member is in fact found that he was illegally abusing illegal substances, drugs, he will be separated from the Coast Guard," Maestas said.
Sources told KGMB-TV that Matthews was going through a difficult time. In 2008 he lost four colleagues in a helicopter crash. In 2009 his first wife was critically hurt when she was hit head-on by a car while she was riding her bike. In 2011 she reportedly took her own life. His disappearance came one year later in 2012.
Matthews remarried after his first wife's death. His wife was receiving administrative assistance from the Coast Guard during his disappearance.
"We can't speculate what the family did or did not know," said Maestas. "As a part of the normal Coast Guard process, the family did receive pay and benefits and allowances, his normal pay and benefits, so we did want to make sure that the family was taken care of."
Sources said his two young children have been staying with family on the mainland.
Matthews has been reinstated to his job as an aviation survival technician. Grief counseling was offered to Matthews' colleagues after his disappearance and were made available again after the new developments.
"This is the first case of this kind that I have experienced in my 28-year career as a Coast Guard member," Maestas said.
What happens next hinges on his medical evaluation to see if Matthews is fit to return to work. Matthews has been a member of the Coast Guard since 1997. He had been stationed at Air Station Barbers Point since 2007.
It's unlikely there will be any criminal investigation unless fraud is suspected. At this point, the Honolulu Police Department has closed its missing person case.