Timothy Busfield's accusers say he touched their kids inappropriately on set ... but the actor-director's lawyer says they're bloodthirsty scammers -- out for either money or revenge.

Busfield's civil attorney, Larry Stein, told NewsNation on Monday that the children's parents have been labeled by the Department of Justice as scammers, and he says they coerced their children to lie about the accusations to get back at Busfield.

Remember ... the kids' father is a disbarred lawyer who reportedly did jail time for cheating people out of millions of dollars -- meanwhile, Stein says the mother got caught passing bad checks at Las Vegas casinos.

According to Stein, the mother was overheard promising to get revenge on Busfield after their kids were discontinued from their shared role on "The Cleaning Lady."

Stein said, "There were 12 or 14 people on set. It would be impossible for Tim Busfield to do what they're alleging with all of those people there, because every single one of them said it did not happen and could not happen."

As we reported ... Busfield was indicted in February on four counts of criminal sexual contact of a minor. He pled not guilty and is out on bail, with a trial scheduled for 2027.