Kristen Stewart's Camp X-Ray co-star Lane Garrison has reportedly moved into her Los Feliz mansion, sparking reports that the two are romantically involved.

In the military drama movie directed by Peter Sattler, Stewart plays the role of a soldier named Cole, assigned to Guantanamo Bay.

"Kristen was enjoying Lane's company and he was spending a lot of time with her at her home," a source told Yahoo's Omg! "He doesn't live in LA so he moved out of his hotel when they became close and moved into the guest wing of her house in Los Feliz."

Stewart had previously shared the house with her Twilight co-star Robert Pattinson, who ended their four-year relationship after finding her cheating on him with married director Rupert Sanders last August.

Meanwhile, Garrison has been convicted of manslaughter charges from 2007, for crashing a car into a tree and killing his passenger, 17-year-old Beverly Hills High School student Vahagn Setian. The former Prison Break star was also arrested for domestic violence, after slapping his former girlfriend and Playboy playmate Ashley Mattingly, outside her Beverly Hills apartment last year.

The On The Road star's brother Cameron is reportedly not pleased with the new happenings.

"Kristen's big brother, Cameron, has told her he's concerned about the new relationship, especially since his recent arrest after his jail term," the insider added, "He's a much darker person than Rob and still goes to mandatory AA meetings every week following his battery arrest. But Kristen is trying to pull her life together and she's been leaning on Lane since they started filming together. She understands his violent past but trusts that he's changed and is really enjoying getting to know him."