Ant McPartlin has been arrested on suspicion of drink driving.
The 42-year-old presenter was picked up by police at 4pm on Sunday (18.03.18) after allegedly hitting two cars in his black Mini sports car while driving with his mother in Richmond, south west London.
One onlooker, Jake Spencer, said the "Saturday Night Takeaway" star was "argumentative" towards cops when they tried to put him in a police car after he failed a breath test.
He told The Sun newspaper: "Ant looked in a right state and was acting argumentatively toward a policewoman.
"I couldn't believe it when I saw who it was.
"The woman was trying to arrest him and get him in the police car but he clearly wasn't having it.
"He was not making it easy for her and he seemed to be trying to wriggle out of her clutches. He was not in a good way.
"Eventually she got him in the police car. There were about six or seven police cars in total."
It is thought Ant - who went to rehab last summer for help with addiction - veered into the wrong lane after coming round a sharp bend, hitting a green Mini before crashing into a BMW X5.
Another witness, who lived nearby, said they rushed out to help because they thought there had been a "train crash".
They said: "I was at home when I heard a huge bang outside which was so loud I thought it was a train crash.
"There's a level crossing nearby and I genuinely thought a train had wiped out a car.
"I went to if anyone needed help. As soon as I opened my front door I heard the horn of a car blaring non-stop and ran towards the sound.
"Near a bend in the road there were two badly damaged Minis which looked as though they'd collided and a BMW X5 -- and people wandering around in shock.
"A family had been in the green Mini which had its front end completely smashed in.
"A little girl aged six or seven was crying as her mum tried to calm her down.
"She looked really shaken up but didn't look seriously hurt. Then I saw the driver of the black Mini, a flash one with red sports stripes and alloy wheels, and recognised the driver as Ant.
"He looked really, really traumatised and unsteady on his feet, which I put down to shock because his car was a wreck. It must have been a big impact because all of the airbags had gone off inside Ant's Mini. He looked awful...
"None of them looked to be seriously hurt. They were just in shock. I think an Asian family were involved and passers-by were helping them before the ambulance and police arrived."
The upset little girl was taken to hospital to be checked over as a precautionary measure.
A police spokesperson said: "Police were called to Lower Richmond Road at 15:59hours following reports of a road traffic collision involving three vehicles. A number of individuals were treated at the scene for minor injuries only.
"A child passenger from one of the cars has been taken to hospital for a check-up as a precaution.
"A 42-year-old man was arrested at the scene on suspicion of drink-driving after failing a roadside breathalyser test."