Ross Kemp got candid about his experience of getting high on Spice in HMP Belmarsh.
Inside prison walls, the former EastEnders star inhaled a microscopic amount of the drug residue left in an inmate's vape which left him unable to speak for a new documentary.
As he failed to do his planned piece to camera after sampling the substance, the actor reflected on his experience when he appeared on Good Morning Britain on Thursday.
Ross pointed out the drug stops people's ability to function - just as he had demonstrated when he was left unable to speak.
"Certainly stopped me from talking for a bit," he mused.
"It stops your ability to function. I wanted to do a piece to camera but I couldn't speak. I had a little bit of residue."
In defence of the prison, the soap star insisted there was not a jail in the world clean of drugs.
Ross claimed the substance was more rare in HMP Belmarsh which made the drug "far more expensive" for prisoners to purchase.
He said: "There's not a prison in the world that doesn't have drugs in it. In Belmarsh, it's far more expensive. Prison reflects in society.
"If there is an increase in gangs, increase in gangs behind bars."
It has been home to murderer Ian Huntley, black cap rapist Joh Worboys and the Lee Rigby killers.
On his visit, 187 murderers and 17 terrorists were behind bars.
Welcome to HMP Belmarsh With Ross Kemp starts on Thursday January 9.
.jpg?w=600)
