By Dan Whitcomb

LOS ANGELES (Reuters) - Police and FBI agents spent a second day on Thursday digging at the edge of a California university campus for the remains of a student who went missing 20 years ago while walking to her dormitory.

The work has yet not uncovered the body of Kristin Smart, 19, who police believe could be buried on a grassy hillside at California Polytechnic State University, 150 miles northwest of Los Angeles.

But a spokesman for the San Luis Obispo County Sheriff's Office told the local San Luis Obispo Tribune newspaper that some "items of interest" had been recovered during the dig, without elaborating.

The sheriff's office has said that new information in the cold case has led them to believe that Smart's remains could be found on the hill, below a 50-foot (15 meter) concrete letter "P" marking the school.

The excavation project has drawn new interest to the case, which is unsolved two decades after the Cal Poly San Luis Obispo freshman's May 25, 1996 disappearance.

Smart had left an off-campus party at about 2 a.m. that morning accompanied by two classmates who believed she should not walk home alone. The group was joined along the way by fellow student Paul Flores.

After they split up on campus, Flores was alone with Smart not far from her Muir Hall dorm. He has told police that he parted company with her there.

Flores was the last person to see Smart alive, according to authorities.

The San Luis Obispo Tribune newspaper reported that after Smart was reported missing by fellow dorm resident, cadaver dogs homed in on Flores' room, specifically the mattress of his bed.

Flores was questioned by police in June 1996 and has been called a person of interest in the case but has not been arrested or charged.

The attorney who formerly represented Flores in the case no longer represents him, according to his office. It was not immediately clear if Flores has retained a new lawyer.

Smart's parents sued Flores and the university for wrongful death, but that lawsuit remains on hold because police records have been sealed during the criminal investigation.

"We are mindful that with or without the hoped-for results from this week’s efforts, we are now on a path that will bring our family peace and comfort,” the Smarts wrote in a statement released to the Tribune.

Delays in the investigation of Smart's disappearance prompted legislation in California requiring colleges and universities to share information about missing students more quickly with off-campus authorities.

(Reporting by Dan Whitcomb; Editing by Dan Grebler)