The South Florida men's basketball program is under NCAA investigation for possible academic fraud issues, multiple sources told ESPN.

South Florida confirmed in a separate statement that one of its athletic programs is being investigated by the NCAA, but offered no further details.

"Because the University of South Florida is committed to protecting the integrity of the investigation and ensuring those involved receive fair treatment, we cannot provide any details about the investigation at this time," the school's statement said.

Assistant coach Oliver Antigua, the brother of head coach Orlando Antigua, had not been allowed to go out on the road recruiting this month, multiple sources told ESPN. The school released a statement later Wednesday saying that Oliver Antigua has resigned, but did not say why.

Orlando Antigua took over in 2014 after spending the previous six seasons under John Calipari -- one at Memphis and five at Kentucky.

Oliver Antigua was previously an assistant for one season at Seton Hall before he was hired to join the USF staff in 2014. He spent more than a decade as the head coach at St. Raymond High in the Bronx.

Orlando Antigua, 43, is 16-47 in his two seasons at the helm at South Florida. The Bulls were 7-24 last season.