The Missouri ER doctor who went missing for more than a week was seen getting into another vehicle with an unknown driver before his body was found in a lake, according to his family.

Security cameras show Dr. John Forsyth entering the car in the parking lot of a public pool in Cassville, Missouri on May 21, his brother, Richard Forsyth, told The Associated Press.

The footage captured some of the 49-year-old doctor’s last known movements before he was found dead Tuesday by a kayaker in Beaver Lake in Arkansas — about an hour south of Cassville. He appears to have died from a gunshot wound.

After entering the unknown car, Forsyth apparently got out before the driver left the parking lot.

His brother had previously told the Daily Beast, citing police, the surveillance video showed Forsyth walking around in the parking lot about “10 to 15 minutes” after the car left.

Forsyth then mysteriously left his own unlocked car behind in the parking lot. Two phones, a laptop and other personal items were found inside his vehicle, his brother said.

Richard Forsyth said his brother had texted his new fiancée around 7 a.m. the day he disappeared, telling her he would see her soon. Then he suddenly stopped responding to messages.

Officials, who remained tightlipped releasing information regarding the case, have not identified the driver of the other vehicle.

Detectives told Forsyth’s brother that the death is being investigated as a homicide, he told OzarksFirst. However, authorities have not said whether or not they believe he was killed or took his own life.

Benton County Coroner Daniel Oxford said an autopsy was completed Thursday. The results won’t be released until the investigation is complete. 

Forsyth was reported missing on May 21 after he failed to show up for his shift at Mercy Hospital, which  was completely out of character for the father of eight, according to his loved ones.

Richard Forsyth said the family had been gathered together eating dinner Tuesday night when a state police officer came to the door to share the tragic news.

Family members have rejected the idea that loving, happy father would commit suicide.

“There’s no way he killed himself,” Richard Forsyth told Fox News this week. “Many times he mentioned he might be in danger.”

He loved his work as a doctor and rarely missed a day of work, often sleeping in an RV outside the hospital when he was on call, family members said. 

His RV was also left unlocked, which Richard also called “very uncharacteristic.” 

Richard Forsyth said that his brother has previously been involved in dangerous situations and that he was 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 he was threatened,” Richard said.

The brother only learned about the kidnapping from a friend, and said John decided not to file a police report because he believed he was in continued danger, he told Fox News.

Richard said he didn’t know who would want to harm his brother.

Forsyth’s connection to the second vehicle seen on pool surveillance video remains unclear. Authorities have not confirmed any information about the video — including if it was taken before or after Forsyth may have texted his fiancée.

Police have also not released any information on how Forsyth got from Cassville to Beaver Lake, when and where he died, or if investigators recovered a weapon.

Shannon Jenkins, spokesperson for the Benton County Sheriff’s Department, told AP Friday that “there is no immediate threat to the public,” but declined to offer additional information until the investigation is complete.

Forsyth had gotten engaged just three days before his disappearance, but he was also recently divorced. On May 10, a judge ordered Forsyth to pay his ex-wife $3,999 in child support a month, plus another $15,000 a month, according to court records.

He married and divorced the same woman twice between 1995 and 2022, but both his brother and Ryan Ricketts, the ex-wife’s divorce attorney, say the split was amicable.

His ex-wife, who lives in Idaho where he was born, was given custody of the couple’s children, though he continued to have a strong relationship with them, his brother and the woman’s divorce attorney said.

Forsyth has been an actively licensed doctor and surgeon in Missouri since July 1, 2005 after receiving his medical degree from Ross University, based in Barbados.

He’d been an emergency physician at Mercy Hospital in Cassville for nearly 15 years.

With Post wires