The 23-year-old actor stars with Michael in upcoming movie 'Wall Street: Money Never Sleeps' and has revealed the 65-year-old screen icon has been left "broken" by his son Cameron's legal woes.

He told German website Gala.de: "I met a broken man, not Michael Douglas the celebrity. This man suffers; he's going through a crisis. He fears for his son. Cameron is facing a prison sentence because of his drug dealing. When I worked with Michael, he would visit his son in prison before he arrived at the set. It was really difficult for him."

Despite his family problems, Shia says Michael was a total professional on set.

Oliver was really sensitive, but he had to finish his film at the same time. That's why there wasn't a lot of time left to comfort Michael. That was tough.
The 'Transformers' actor admits he and director Oliver Stone wished they could have done more to support Michael.

Shia explained: "Oliver was really sensitive, but he had to finish his film at the same time. That's why there wasn't a lot of time left to comfort Michael. That was tough."

Cameron is facing a possible 10 years in jail after pleading guilty in January to possession and dealing methamphetamine and cocaine from a Manhattan hotel last July.

Michael - who has two other children, Dylan, nine, and six-year-old Carys, with his wife Catherine Zeta-Jones - recently confessed he could have been a better father to his 31-year-old son

The 'Sentinel' star - whose father is screen legend Kirk Douglas - said: "My priorities were very similar to my father's. Career first. The history of second-generation actors isn't great in our industry. It's kind of a tragic road, actually. Anybody who has a relative or child in substance abuse has some idea of what this feels like. This is one of those worst-case scenarios. It will ultimately be a painful lesson.