Reformed hellraiser Colin Farrell admitted he was on the brink of going on a lethal heroin binge before getting clean.

The Castleknock hunk, 37, revealed the daily struggle as he battled his demons on the set of blockbuster flick Miami Vice.

He said: “I’m off the jar seven or eight years. I can tell by the last film I did when I got off it. It was interesting because I couldn’t remember a single frame of doing it.

“I was at the premiere and didn’t know what was happening next. But it was strange because I was in it.

“The movie was Miami Vice. The second it was finished I was put on a plane and sent to rehab as everyone else was going to the wrap party.”

Farrell also talked about his harrowing relationship with drugs and how it nearly made him lock himself away and take a fatal amount of heroin.

He told Ryan Tubridy on the Late Late Show: “For years I could indulge in certain things. I had high tolerance for various drugs for years.

“I used to go bananas for five months then take the foot off the gas for two months and clean up a bit.

“I was sad. I was drinking loads.

“When I ever drink with my mates, we’d go to a pub on Wednesday night and have six pints, everyone would go home.

“I’d get a bag of powder, four joints and a bottle of Jack Daniel’s and drank until five in the morning.

“It was already in me. My family were trying to get me into rehab. And I’d get angry with them and say, ‘Go get the men in the white coats and see if I don’t stab ’em to death’.

“I remember thinking one day that I’ll go to New York, buy €2,000 worth of smack and rent a bedsit, put black sacks on the window and shoot up until I die. The other choice was to change. I was clear about it. I chose the right one.”

During this dark period, the dad of two experienced many highs and lows with the leaking of a sex tape online being one of his lowest points.

And the Phone Booth star revealed for the first time how porn bosses offered him $5million (€3.5million) to distribute the X-rated 14-minute video worldwide.

In 2003, he privately recorded the raunchy session with Playboy model Nicole Narain. When the tape was leaked three years later, he sued her over the unauthorised public distribution.

Even though the actor confirmed its existence and obtained a court order blocking its distribution in January 2006, copies of the tape appeared online.

But Colin said he couldn’t bring himself to sell it. He explained: “I was offered that amount of money to do it. It was ridiculous. I said absolutely not because it was going to be on hotel rooms on demand and stuff. Then I was thinking of my mam going into a hotel room and saying, ‘Ooh, there’s a film with Colin I haven’t seen’. I couldn’t have that.”

But away from the tough battle against addiction, Colin revealed that his proudest moments now are watching his children grow up. His eldest child James, 10, suffers from Angelman syndrome – a neuro-genetic disorder with symptoms including intellectual and developmental disability, seizures, jerky movements and sleep disturbances.

Colin said it’s watching his boy do the little things, which people take for granted, that fills him with most pride.

He added: “We share in the smallest victories – the first words at age six or seven, being able to feed oneself and getting the seizures under control. When James took his first steps at age four, I nearly broke in half.

“My proudest moments are moments I’ve experienced by proxy. James is dynamite, he’s magic, his trials and tribulations. He’s a little bit more unique than most.

“To watch him face the hurdles in front of him, it’s an inspiration. My greatest success is watching him achieve his goals.”

And now that he’s left his bad-boy image behind him, Colin still rubs shoulders with other famous faces and indulges in exercise to de-stress.

He added: “Yoga. It’s a bit of craic. I do an hour a day and it’s great fun. Back in the day if I said to someone I was doing it, they’d say to me, ‘Will ya f**k off, go away outta that’.

“If I met with me I’d say, ‘What a Mary; get away from me’, but I love it. I’m very, very lucky.”