The Missouri ER doctor whose body was found in an Arkansas lake Tuesday was murdered, his brother told Fox News Digital.

The Benton County Sheriff's Office issued a press release Wednesday saying John Forsyth, 49, was discovered dead from a gunshot wound in Beaver Lake by a kayaker who called 911 at 4:43 p.m.

Officials declined to comment on whether Forsyth's injury was self-inflicted, but his brother, Richard Forsyth, said his brother was murdered. 

"They are treating this as a homicide," Richard told Fox News Digital, referring to detectives who visited the family Wednesday evening. "They said it’s important to understand that the autopsy has not been finalized, and a report hasn't been issued."

MISSING MISSOURI DOCTOR FOUND DEAD IN LAKE FROM GUNSHOT AFTER PREVIOUS KIDNAPPING REVEALED

Dr. John Forsyth photo next to Beaver Lake

The body of Dr. John Forsyth, who vanished May 21, turned up in Beaver Lake in northwest Arkansas. (Google Maps/Cassville Police Department)

Richard added that the Benton County Sheriff's Office is sharing few details to maintain the integrity of the investigation but assured the family it has dedicated tremendous resources to the case.

"To hear this news, it was shocking to the extreme and, of course, blew all of our theories out of the water," said Richard, who had hoped that his brother had disappeared to protect himself and others from danger.

MISSOURI ER DOCTOR WHO VANISHED 3 DAYS AFTER PROPOSING TO FIANCEE FOUND DEAD

But the nature of that peril remains a baffling mystery to his family. Forsyth vanished May 21 after wrapping up his shift about 7 a.m. at Mercy Hospital in Cassville, a town of about 3,000 in the Ozarks. 

The father of eight finalized his divorce in mid-May with an order that required him to pay $19,000 a month in alimony and child support. 

The couple had previously divorced and remarried before their latest split. His ex-wife's divorce attorney, Ryan Ricketts, told Fox News Digital she is "very shellshocked" by Forsyth's death.

Entrance of Mercy Hospital

Dr. John Forsyth failed to show up to work for his 7 p.m. shift at Mercy Hospital in Cassville, Mo., May 21.  (Google Maps)

A few days after the divorce decree, Forsyth proposed to his fiancée, with whom he was texting when he suddenly stopped responding to messages. 

That night, the Cassville Police Department located his black Infiniti about one mile from the hospital near a waste facility.

PUBLIC SCHOOL EMPLOYEE WANTED FOR KIDNAPPING TAKES COPS ON HIGH-SPEED CHASE SPANNING MULTIPLE COUNTIES: POLICE

His wallet, two phones, car keys and a passport were still inside. The luxury RV where he stays during his shifts was still in the hospital parking lot unlocked and contained his three other phones, his laptop and keys.

An extensive ground and canine search by the Cassville Police Department and the Missouri State Police turned up no clues. 

Dr. John Forsyth next to a missing person's poster

Missouri Dr. John Forsyth vanished May 21 after he failed to show up to work at a local hospital. (Cassville Police Department/Facebook)

The discovery of Forsyth's body about an hour south in northwest Arkansas stunned his family and has left relatives in fear for their own safety.

"We don’t know who harmed him or for what reason and whether they plan to continue their aggression," Richard said.

TEXAS WOMAN SAYS SHE'S CHICAGO MISSING CHILD FROM OVER 20 YEARS AGO: REPORTS

The brother also learned from a friend shortly after Forsyth went missing that he had been kidnapped and released in February 2022. 

"It was cold. He was zip-tied. He was made to feel very unsafe and taken on a car ride with some people to a bridge and was threatened," Richard said.

Map of Cassville Aquatic Center and a photo of Dr. Forsyth

Dr. John Forsyth, right, and a map of the Cassville Aquatic Center where police located his black Infiniti sedan Sunday. (Google Maps/Facebook)

He added that his family was unfamiliar with Beaver Lake.

"None of us had ever even heard of it," he said. "I don’t know of any connection my brother had with northwest Arkansas."

CLICK HERE TO GET THE FOX NEWS APP

Richard and his slain brother shared a love of mathematics and launched several business ventures together, including the creation of their own cryptocurrency.