Military authorities are investigating the death of a Camp Pendleton-based sailor found in a guard shack, and local gay activists said it may have been a hate-crime slaying at the hands of a fellow serviceman.

August Provost of Houston, Texas, was found dead on the western side of the North County Marine Corps base about 3:30 a.m. Tuesday, said Doug Sayers, a spokesman for Navy Region Southwest.

Investigators consider the death of the 29-year-old boatswain’s mate a possible homicide, though a final determination is on hold pending autopsy results, Sayers said. He confirmed that a “person of interest” in the case has been arrested and is being held in a Camp Pendleton brig.

The potential suspect’s name was not released. Ben Gomez, head of the San Diego chapter of American Veterans for Equal Rights, a national advocacy group for gay and lesbian military personnel, said he and other local activists believe Provost’s death was a hate crime.

Citing unnamed sources with access to a report on the seaman’s death, Gomez said Provost was killed during an argument with another sailor over the victim’s sexual orientation.

On his MySpace page, Provost made references to same-sex dating and identified another Houston man as “the love of my life.” Provost, who enlisted in the Navy in March 2008, was a member of Assault Craft Unit 5, whose personnel are assigned to duties involving hovercraft.