Additional charges will be filed against a Centennial High School teacher and coach accused of the sexual abuse of a teenage student, Ada County authorities say.

Daniel Douglas Campbell, a 41-year-old biology teacher and assistant wrestling coach, is charged with one count of lewd and lascivious conduct involving a 14-year-old girl.Sheriff Vaughn Killeen made a public plea for assistance Thursday, asking parents, teachers and youths with relevant information to contact his office.

Detective Steve English said 40 to 50 Ada County girls with links to Campbell are being investigated as potential victims. Many have so far been identified by first names only.

Killeen said, "Basically we have indications that things were occurring that wouldn't exist in a normal student-teacher relationship."

English, who is also school resource officer at Centennial High, said he is not aware that any incriminating information concerning Campbell reached school officials before the defendant's April 12 arrest.

"This is a total surprise to us," said Bob Haley, Meridian School District secondary education director. "We didn't have even the slightest inkling that something like this could be going on."

Authorities claim Campbell, a Meridian teacher for 10 years, carefully cultivated relationships with teenage girls, spanning months or even years.

Campbell, deemed a suicide risk, is being held in an undisclosed secure medical facility in lieu of $100,000 bail. The unmarried teacher has been suspended with pay by the school district pending resolution of the case.

Ada County Deputy Prosecutor Julianne Meehan said additional charges are "forthcoming" against Campbell but declined to elaborate on what they could involve.

Defense attorney Fred Frahm of Boise criticized authorities for fanning public hostility against his client with such a premature announcement.

The existing criminal charge alleges Campbell had sexual intercourse with the then 14-year-old girl between September and November 1989.

At that time, Campbell was a science teacher and football coach at Meridian's Lowell Scott Middle School, and the girl was a student. She is now 16.

Authorities say Campbell impregnated the girl, then posed as her father in arranging for an abortion.

Under Idaho law, physicians must notify parents or legal guardians "if possible" at least 24 hours before performing abortions on girls under 18.

Killeen said searches of Campbell's homes in Boise and at the Wilderness Ranch near Idaho City yielded evidence, including hundreds of letters, indicating "he was intimately involved with many juvenile females."