Oscar winner says other issues contributed to split as well

Oscar winner Hilary Swank is alleging that her marriage to Chad Lowe crumbled at least partially due to his substance abuse problems.

In an interview with Vanity Fair, Swank says that Lowe is clean and sober now, but that he's battled addiction in the past.

"I knew something was happening but I didn't know what," Swank says.

She continues, "When I found out, it was such a shock because I never thought he'd keep something from me. And yet, on another level, it was a confirmation of something I was feeling that was keeping us from being completely solid."

Excerpts from the VF article have appeared in the New York Post, and offer some insight into the decline of a couple thought to be one of Hollywood's most stable.

"I don't want to make it seem like that's the sole reason; there were other factors," Swank says. "But that just kind of blew it open. It made me look at things a lot deeper. That's when you realize it's not going to work."

Swank and Lowe met at a party back in 1992 and married in 1997. At the time of their marriage, Lowe was an Emmy winner for "Life Goes On," while Swank was best known for "The Next Karate Kid." Since then, though, their careers have gone in different directions, with Swank snagging Oscars for "Boys Don't Cry" and "Million Dollar Baby." The actress denies, though, that the divorce has anything to do with their relative degrees of fame.

"Chad is very supportive of my career," she says in the interview. "He is, I think, genuinely happy for my success... I think that any frustration for him stemmed from the lack of opportunities in his own career."

Lowe opted not to comment for the Vanity Fair story.

The couple separated back in January. Swank officially filed for divorce in late May.