Prosecutors say there is an ongoing investigation into a former youth minister at a Camarillo church who is charged with sexually assaulting and molesting three girls.

The investigation is one reason that the District Attorney's Office moved last week to have Markus "Mark" Holland McDowell's bail raised from $50,000 to $120,000, said Senior Deputy District Attorney Gilbert Romero.

Romero told Ventura County Superior Court Judge Kevin McGee on Monday that McDowell complied with the court order and posted a $120,000 bail and turned in his passport.

Romero said it was necessary to raise the bail because of the number of alleged victims and the ongoing investigation. He declined to elaborate on the investigation.

"I was concerned that he might flee," Romero said.

Last week, McDowell, 46, of Camarillo, pleaded not guilty to all the charges.

His lawyer, Brian White of San Diego, said in an interview that the allegations are "extremely old," with the most recent occurring 10 years ago.

"It's a very difficult time for Mr. McDowell," White said. "I have not had a chance to evaluate the evidence thoroughly and explore all the allegations."

The alleged victims were 14, 15 or 16 years old when the suspected actions took place, said Romero.

"He is being charged with a 13-count complaint alleging child molest starting about 1992 to about 1998," said Romero.

According to the Ventura County Sheriff's Department, McDowell met the girls through a youth ministry program at Camarillo Church of Christ, which he served as a youth minister.

McDowell is also charged with one count of possessing child pornography, which authorities said were retrieved from a home computer. Romero said he can't say how many images were retrieved from the computer.

McDowell taught religious courses at Westmont College and Pepperdine University, according to officials at the two institutions.

He was working at Westmont College in Santa Barbara last Spring, said Nancy Phinney, director of the college's Public Affairs Office. She said he was an adjunct assistant professor, which means he was working on a contractual basis.

Phinney said he worked at Westmont for two years during the 2005-06 and the 2006-07 school years. McDowell's contract will not be renewed and "he will not return in the Fall," said Phinney.

McDowell taught five different classes — elementary and intermediate Greek; the life and literature of the New Testament; the writings of the Apostle Paul, and the Gospel and writings of the Apostle John, according to Phinney.

McDowell was a full-time lecturer and adjunct professor at Pepperdine from 1996 to 2005, said Wileen Wong, spokeswoman for the university. He was a religious professor at the university.