"We don't think he's going to make it," the source told FanHouse on Wednesday evening.
FoxSports.com's Alex Marvez reports that Henry is on life support.
"We ask everyone to pray for Chris," agent Andy Simms of PlayersRep Sports said in a statement. "We also ask that you respect the privacy of Chris' family. Chris is indeed battling for his life tonight, and our thoughts and prayers [are] with him during this extremely difficult time."
According to Charlotte-Mecklenburg police, Henry was injured in a domestic dispute during which he apparently fell from the back of a moving pickup truck. Police said Henry jumped in to the bed of the truck as his girlfriend was driving away, and that they found him in the road. Reports said Henry was taken to Carolinas Medical Center, but a hospital spokseperson has denied that Henry is or has been a patient there.
"We obviously are aware he was in an accident and his injuries are very serious," Bengals spokesman Jack Brennan said. "That's all we have at this point. A report quoting me saying he had died is completely false."
That "report" came in the form of an apparently fake Twitter account purporting to be that of a Dallas Morning News reporter around 7 p.m. EST on Wednesday. As of that time, FanHouse has confirmed, Henry was in fact still alive, though in very serious condition.
Henry, 26, was placed on injured reserve earlier this season after breaking his forearm in a game against the Ravens. He has played all five seasons of his NFL career with the Bengals.