SNOHOMISH COUNTY, Wash. -- A Snohomish father says the U.S. Marine Corps is covering up the cause of his son's death.

Lance Cpl. Canham was five days into his first deployment when he mysteriously died in March. He was stationed at Camp Lemonier in the African nation of Djibouti.

He was 21 and newly married when he died.

The official cause of death, according to the Marines, was natural causes, possibly related to an enlarged heart.

Canham's father, Mark Canham, doesn't believe that. He said he saw a bruise and a laceration on his son's face. Canham thinks his son died at the hands of a superior.

"The lightest way I can say it is he took him in and made him do stuff in the tent, I think he booted him in the face or hit him with a gun butt," said Mark Canham.

He thinks Dustin Canham was being punished for accidentally chipping the tooth of another Marine.

A Marine investigator told Mark Canham that Dustin Canham was doing physical training instead of getting a black mark on his record, but after three minutes alone in a tent with two superiors he was dead.

"My son was one of the best people I ever met in my life, that's as a person, not a dad," said Mark Canham.

The Marine Corps Central Command tells us they're conducting an independent and separate investigation to determine what happened and who's responsible.