Matthew Vaughn had panic attacks making Lock, Stock and Two Smoking Barrels

Matthew Vaughn has opened up about the toll Lock, Stock, and Two Smoking Barrels took on him mentally.

Speaking with SFX magazine, the producer disclosed that even though it became his break into Hollywood, stress from the 1998 movie caused him to have panic attacks.

"When we made Lock, Stock and Two Smoking Barrels that was the most pressure I ever had in my life," the 49-year-old admitted, noting that the film cost just "900 grand" to make.

To give the crime comedy its gritty, authentic feeling, Vaughn and director Guy Ritchie cast real ex-cons in some of the smaller roles.

"I had a real gangsters saying they were going to blow my knees off if their part was cut out - and they couldn't act. I thought, 'I'm definitely cutting them out!'," Vaughn recollected.

Furthermore, much of the production was funded with loans from friends, which intensified the pressure.

"(I) got friends to give me money so I had to get their money back. It's the only time in my life I've ever had a f****** panic attack," Vaughn revealed.

Now working as director, writer, and producer on the upcoming Kingsman prequel, The King's Man, Vaughn said he enjoys his job.

"This is fun. I love it," he enthused, adding: "I don't feel pressure when I'm making movies. I'm enjoying it. It's like I'm being paid to play."

Reflecting on the contrast between his outlook now and when he worked on Lock Stock, Vaughn mused: "It's probably because I know what pressure is from when I was younger. When you're broke and you're worrying about your rent and you're making a movie and you really have no f****** idea."