BANGOR, Maine — The Rev. Robert Carlson was under investigation by the Maine State Police before he was found dead in the Penobscot River on Sunday, according to Stephen McCausland, spokesman for the Maine Department of Public Safety.

The investigation started “last Thursday at the request of the Penobscot County District Attorney’s Office,” McCausland said late Monday afternoon. “State police began an investigation of Carlson and this was after the DA’s office had received a letter.”

“I’m not getting into” what the investigation was about, he said.

A Bowdoin woman said Monday that she and several other family members were contacted by a state police detective on Friday and Saturday and interviewed about a child sex abuse case from the 1970s involving Carlson and her brother, who was 11 at the time.

Boy Scout leaders at the Katahdin Area Council also said they turned over a letter concerning Carlson to state police detectives on Monday that includes allegations of child sex abuse.

“Marshall Steinmann, our council’s Scout executive, received a letter this morning concerning this matter and … immediately turned it over to the Maine State Police,” Daniel Lee, president of the Katahdin Area Council, said in an email Monday afternoon.

“Questions concerning the contents and nature of the letter should be directed to the Maine State Police,” he said later. “The Katahdin Area Council is presently unaware of any such allegations concerning scouts past or present.”

Lee also said, “Although his church used the Scouting program as a part of its overall ministry, to our knowledge Rev. Carlson was never a registered member of the Boy Scouts of America.”

Carlson was a former pastor of the East Orrington Congregational Church.

Carlson and his wife, Elaine, were honored last week when the Katahdin Area Council of Boy Scouts of America held its 15th annual Distinguished Citizen Award Dinner.

Penobscot County District Attorney R. Christopher Almy declined to comment on the investigation Monday, saying only, “This conversation is over.”

The Rev. Carl Schreiber of East Orrington Congregational Church said Monday night that Elaine Carlson had no comment about the investigation involving her husband.

Carlson helped found and was president of Penobscot Community Health Care; was a founder of Hope House, a Bangor shelter for those with drug and alcohol addictions; and was a previous chaplain for Husson College as well as the Bangor and Brewer police and fire departments, according to a recent Bangor Daily News story.

Dawn Krog of Bowdoin said the second she picked up the phone on Friday and heard the voice of Maine State Police Detective Jay Pelletier, “I knew it was about Bob Carlson.”

“My brother came clean to the family” a couple of years ago about what she described as an ongoing sexual relationship he had with Carlson, Krog said.

“Bob had been part of his life since he was 12 years old,” Krog said. “Everybody [in the family] knew.”

Krog also said the news about Carlson’s death was difficult for the family.

“It’s just hard when you hear all the people’s comments about what a big loss this is, especially when you know different,” she said.

Another relative from Alton, who asked not to be identified, said she also was interviewed by Pelletier on Saturday.

Carlson befriended Krog’s mother, who was single and had six children, in the 1970s when the family lived in Orrington, both women said.

After Krog’s brother revealed his relationship with Carlson, the Alton woman asked him why he never went to police.

“Back then he was a pastor at Orrington and ‘Who would have listened?’” was his basic response, she recalled.

No charges ever were lodged against Carlson in the 1970s.

The two relatives said they did not know how police got their names and those of others in the family.

Both tried to contact their loved one, but he did not return their calls. The Bangor Daily News is not identifying him because of the possibility that he is a victim.

Penobscot Community Health Care officials said they were not aware of any investigation or allegations involving Carlson when asked during a news conference early Monday afternoon at the nonprofit’s administrative headquarters on Maine Avenue.

“We certainly don’t,” CEO Kenneth Schmidt said. “This is the first mention I have heard of anything like that. I know of no reason that there should be [an investigation]. He’s never spoken of anything to me. I was a close personal friend, as was Dr. [Robert] Allen,” executive medical director of PCHC.

“There were no issues, for that matter, with PCHC, whatsoever,” Schmidt continued. “I have no idea about anything like that. I wish I did. Rev. Bob was a man of enormous integrity and caring and I think that’s how all of us will remember him, no matter if anything comes up.”

Administrative officials at Husson University, where Carlson served as school chaplain for 12 years when it was known as Husson College, were asked Monday why he left the post, but they declined to comment.

“Due to the ongoing Maine State Police investigation, Husson University has no comment,” said Julie Green, Husson’s director for public affairs and government relations.

Sheriff Scott Story of the Waldo County Sheriff’s Office said that no suicide note was found in Carlson’s vehicle and there was no indication of foul play in his death.

A Bucksport woman called authorities at 3:55 a.m. Sunday to report that a vehicle had been abandoned in the middle of the Penobscot Narrows Bridge, according to a press release issued Monday by the sheriff’s office.

When deputies arrived at the bridge, they found identification belonging to Carlson in the vehicle, which was parked on the right side of the eastbound lane.

Officials began to search the river and found his body in the water later in the morning, according to Chief Deputy Jeff Trafton.

An autopsy was completed Monday afternoon at the state medical examiner’s office in Augusta. It determined that Carlson drowned, but the manner of his death is still pending, said Mark Belserene, administrator of the state medical examiner’s office.

Police officers were busy Monday doing such things as examining the contents of Carlson’s car and interviewing the people he had last contacted. There were no known eyewitnesses and no indication that anybody else was involved, Story said, adding that he was thankful Carlson’s body was found quickly.

“I think we were fortunate to find him so fast,” the sheriff said.

Police expect that the investigation into Carlson’s death will be wrapped up later this week at the earliest, with Detective Merl Reed of the sheriff’s office assigned as the primary investigator on the case.

Half a dozen people have been interviewed as part of the Maine State Police investigation, McCausland said. Detectives had not spoken to Carlson, 68, before his death, he said.

“The investigation remains open at this point,” McCausland said.

BDN writers Abigail Curtis, Andrew Neff and Dawn Gagnon contributed to this report.