BOULDER, Colo. -- A Marine suspected of staging his disappearance to avoid duty was officially still on leave Tuesday, and investigators said they are pursuing several leads in their search for the man.

Lance Cpl. Lance Hering, 21, was reported missing by a friend who said he was injured in a hiking accident Aug. 29, but sheriff's deputies said the friend, Steve Powers, changed his story to say the disappearance was faked.

Powers was arrested last week on a false reporting misdemeanor charge.

His family has said Hering would not have faked such a disappearance. They said he may have suffered a head injury that left him disoriented.

Hering's father, Lloyd Hering, pointed out that Powers lied for 10 days while searchers scoured the canyon for their son. So why, he asked, would Powers now be telling the truth?

Powers originally told authorities Hering lost consciousness after falling while the two were hiking in the foothills northwest of Denver.

Powers said he went for help but couldn't find Hering when he returned. Sheriff's officials planned to seek restitution for the thousands of dollars spent on a five-day search for Hering.

"The truth is that no one we can depend has seen Lance since that moment that he left the house," said Lloyd Hering. "His fate and his location are a complete mystery. If anything the mystery has gotten deeper as the search went on."

Hering's parents have another theory of what may have happened to their son.

"It may be that Lance is a victim of foul play," said Lloyd Hering.

They said they just want to know that their son is OK.

"Please call home, pal. Please call home," said Lloyd Hering.

Boulder County Sheriff Joe Pelle said investigators were reviewing bank, credit, computer, mobile phone and other records to try and locate Hering.

The Marine Corps has classified Lance Hering as "duty status unknown," said 1st Lt. Esteban Vickers, a spokesman for Camp Pendleton, Calif., where Hering was due to return to duty Sept. 18.

The sheriff's department had said last week Hering was due to return to duty Sept. 11. Sheriff's Cmdr. Phil West blamed the discrepancy on confusing paperwork sent to his agency by the Marines.

If Hering does not show up on Sept. 18, he would be considered away without leave, said Master Sgt. Cindy Grubbs. If he fails to show up within 30 days of Sept. 18, he would be considered a deserter, she said.

"Our number one concern is that this Marine is safe and unharmed," Vickers said.

"We have several leads we're following," Pelle said.

Pelle said deputies were not sure whether Hering had left Colorado.

Hering faces a Boulder County arrest warrant that accuses him of violating the terms of a deferred sentence he received after pleading guilty to a burglary and obstructing a police officer in a 2004 break-in. Under terms of his sentence, he could avoid penalties if he stayed out of trouble for two years.

Hering is with the 3rd Battalion, 5th Marines, 1st Marine Division based at Camp Pendleton, Calif., that returned from Iraq early last month, military officials said. Hering was not expected to return to Iraq until at least 2008.