SAN DIEGO » A San Diego man was charged Monday with lying to the FBI during an investigation into his brother, who is believed to be the first American jihadist killed in Syria while fighting for the Islamic State.

Marchello McCain, 33, is accused in an indictment of providing false information about his brother’s travel to Syria and how he financed the trip, federal prosecutors said.

McCain already faces gun possession charges.

His lawyer did not immediately return a request for comment.

The brother, Douglas McCain, 33, was reportedly killed a year ago while fighting with the Islamic State, the extremist group trying to overthrow the government of President Bashar Assad.

Douglas McCain traveled to Syria to follow his basketball buddy from Minneapolis into the terrorism fight.

Douglas McCain, who last lived in San Diego, once said in a Twitter feed that embracing Islam was the best thing he’d ever done. He was following Islamic State group fighters on Twitter, but it’s unclear what prompted him to join the fight.