Christian Slater and his father are involved in a "long and difficult" situation.
The 'Mr Robot' actor is being sued for $20 million by his estranged parent Thomas Knight Slater - whose stage name is Michael Hawkins - for comments he made last year saying his dad was "suffering from manic-depressive schizophrenia" but insiders claim the legal action is "baseless".
A source said: "It's been a long and difficult situation. The lawsuit is baseless."
Christian is said to have "done what he can" for his father - whose last credited role was in 1988 movie 'Midnight Run' - but distanced himself from the 80-year-old actor because of his "erratic" antics.
The source told People magazine: "His father has had his troubles. Christian has done what he can for him financially by supporting him for many years, but eventually had to distance himself because of his erratic behaviour."
In his legal action, the 'Amityville Horror' actor accuses ex-wife Mary Jo Slater and the 'Heathers' star of slander, libel, defamation of character, intentional interference with prospective economic advantage, and invasion of privacy, as well as intentional infliction of emotional distress.
And Thomas also noted Christian - who had made the comments last July - didn't have the "medical credentials" to correctly diagnose him with any condition.
Speaking to director Lars Von Trier for Interview magazine, Christian discussed his estrangement from his father and said the elder actor had "always had trouble" working with other people.
He said: "He's a manic-depressive schizophrenic.
"He's always had trouble - he was a fantastic actor and extraordinarily charismatic and very, very good looking, but he had a really difficult time working with directors, collaborating with people."
Thomas has demanded a trial by jury.