AUTO: MAY 01 IndyCar - Barber Motorsports Park
Getty Images

NASCAR driver Jimmie Johnson's in-laws, along with one of their grandchildren, were found dead in Muskogee, Oklahoma, on Monday night in what police suspect was a murder-suicide, according to multiple reports

The bodies of Jack Janway and Terry Janway -- the parents of Johnson's wife Chandra -- and 11-year-old Dalton Janway, Chandra's nephew, were found following a reported disturbance involving a gun. Law enforcement officials told Fox 23 that Terry is a suspect

The investigation is still ongoing, with no motive known yet.

Local newspaper the Muskogee Phoenix reported that dispatch received a 911 call at approximately 9:05 p.m. local time from a woman who reported a disturbance involving a gun. She then hung up the phone. When officers went inside the house of where the disturbance was taking place, they found 69-year-old Dr. Jack Janway -- Johnson's father-in-law -- lying in the hallway. Soon after, they heard a gunshot from further inside the home.

More officers arrived at the scene and found 68-year-old Terry Janway, Jack's wife, as well as their 11-year-old grandson, Dalton Janway, dead in a different part of the house.

On Tuesday, Legacy Motor Club announced it is withdrawing the No. 84 Carvana Chevrolet from the Chicago Street Course race taking place this coming Sunday. 

"The Johnson family has asked for privacy at this time and no further statements will be made," read the statement from the team posted on social media.

NASCAR retweeted the Legacy Motor Club statement, but has not released anything else.

Johnson has been married to Chandra since 2004.