Gary Oldman apologised to Demi Moore for his "destructive" behaviour on the set of 'The Scarlet Letter'

He told Radio Times magazine: "I think the worst thing you can do is inspire disappointment.

"I was in 'The Scarlet Letter' with Demi Moore, and I had intermittent bouts of boozing during filming.

"It was towards the end of [my drinking] where I thought, 'If I carry on like this...'

"I was in a very dark place. I drank too much in the lunch hour. It was such a destructive thing. I got back on the set to do quite a big scene and I got through it."

Although it wasn't apparent in his performances, the 'Harry Potter' star confessed he was "quite tipsy" during filming.

He added: "You wouldn't really know but I was quite tipsy. And the next day, I said to her, 'I'm so sorry, you must hate me.'

"I was mortified that I'd been so unprofessional. And she said to me, 'I don't hate you. It's OK. I'm just disappointed.' "

In 1991, he was arrested for drunk driving, and voluntarily checked himself into rehab three years later.

Gary - who has now been sober for 27 years - recently heaped praise on Demi for her recent success after her role in 'The Substance' earned the star a Golden Globe and SAG Award.

He told the New York Post newspaper: "I couldn't be happier for her in this moment with this film and this role.

"I think it's such a wonderful thing. And she's loving it and really riding the wave."

Speaking to the outlet in February, Gary revealed the pair had "reconnected" after years of not really keeping in contact.

He added: "I've not really been that in touch with her, but I just actually reconnected with her because I've seen her recently.

"She is such a wonderful person, Demi. She really is very special."