One of TV's most promising train-wreck shows looks like it has been derailed before it could leave the station.

Actor Jason Mewes (search) is trying to kill a much-publicized documentary - originally set for HBO - chronicling his heroin addiction and rehab.

Mewes agreed to let the HBO filmmakers tape everything related to his addiction - including him shooting up.

Now Craig Veytia (search), who's producing Rock Bottom, is suing Mewes for pulling out, according to Court TV's thesmokinggun.com.

And HBO has decided to pass on the project, a network spokeswoman told The Post yesterday.

Mewes, 28, inked a deal with Veytia in mid-March for Rock Bottom, which would chronicle Mewes' heroin addiction and his struggle to get clean. He is currently in rehab.

Veytia's suit, filed June 20, claims Mewes has tried "to hinder and/or prevent" the documentary.

Martin Arbus, an attorney who's representing Mewes, said "it's a possibility" that his client will try to put the kibosh on the documentary once he's out of rehab.

"Jason has not seen what is on this film . . . and until he sees what they've done, no final decision will be made," he said.

"I've requested that any discussion or resolution of this issue await Jason's release from the facility he's in so he can better deal with this issue.

"Obviously, they've chosen not to wait, which is unfortunate," said Arbus.

HBO's decision to drop the film seems to have played a big role in the dispute.

"This was held out to [Mewes] to be an HBO documentary, when in fact [Veytia] doesn't have approval from HBO to do it," said Arbus.

Veytia's attorney did not return a call seeking comment.

Mewes, 28, shot to fame as the fast-talking, pot-smoking drug dealer featured in buddy Kevin Smith's movies Clerks, Jay and Silent Bob Strike Back, Mallrats, Chasing Amy and Dogma.

He pleaded guilty last April to six counts of violating his probation for a 1999 heroin conviction.

At the time, Smith told The Post that he thought the idea of cameras documenting Mewes' struggle to get clean and sober was "exploitative."

Two weeks ago, Mewes transferred from one drug treatment facility in New Jersey to another - saying members of the first center were treating him "adversely" because of his celebrity status.