Updated 08/01/12 - 8:32 a.m.
HAMMOND, Ind. (CBS) -- The longtime pastor of a northwest Indiana church has been dismissed due to an "improper relationship with a young woman."
Dr. Jack Schaap, who has been pastor of First Baptist Church in Hammond for 11 years, was removed Tuesday, according to a church spokesman.
The spokesman would not provide the woman's age, but said she was a member of the church.
LISTEN: WBBM Newsradio's Steve Miller reports
A former member of First Baptist and now founder of a Facebook site for former First Baptist members, Trisha Kee, says her group has received information about Pastor Schaap.
"Jack Schapp had left his cell phone on the pulpit and a deacon had seen it on the pulpit and had picked it up to bring it back to him," Kee said. "From what we understand, the deacon then saw a text come through from a teenage girl in the church, and it was a picture of Jack Schaap and this girl making out."
Kee says she understands the girl had been going to Schaap for counseling, and she says another young woman has also come forward.
"She was also going to him for counseling," Kee said.
A church spokesman could not confirm Kee's information, but he did say Schaap was in an improper relationship with a young woman and that they thought she was above the age of consent.
In a written statement, the church spokesman, Eddie Wilson, added that Schaap was removed "due to a sin that has caused him to forfeit his right to be our pastor."
"Our church grieves over the need to take this action and the impact it will have on our people", Wilson added. "We ask that everyone pray for the families involved, and pray that the situation will be handled in a Christ honoring manner. We look forward to the days ahead as we continue to service the needs of our surrounding community and the Chicago area."
Lake County Sheriff John Buncich said his department was notified by church leaders of allegations that are sexual in nature. CBS 2's Brad Edwards was told that, when confronted, Schaap admitted to his sins to the church's governing body of deacons.
The FBI has also joined the Lake County Sheriff's office in the investigation.
FBI spokesman Robert Ramsey said: "It is too early at this point to release any further information."
The church is a conglomerate that includes a 7,500 seat auditorium and is headquartered in the old federal courthouse in Hammond, IN. Schaap helped grow the church into its 'mega' status with 15,000 people attending weekend services, according to Wilson.
Parishioners were shocked when they heard the news.
Norma Hogan described the pastor as "very charismatic, very magnetic."
"He's always saying how his wife is beautiful and so much in his life," Hogan added. "This is jaw dropping."
The church has scheduled a meeting for the entire congregation for Wednesday night.
Schaap is married to the daughter of the church's late leader, Rev. Jack Hyles.
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