A lawyer representing Jason Patric has vehemently denied allegations the actor mistreated the mother of his son.

The Speed 2 star is currently embroiled in a high profile custody dispute with his ex-girlfriend, Danielle Schreiber, over their four-year-old son Gus, who was born through artificial insemination.

Patric has spent the last few years fighting for access to his son as U.S. law only recognises him as a sperm donor with no paternity rights, but a California appeals court recently gave his claim a boost by granting him permission to claim parentage of Gus.

However, Patric has now been hit by a slew of nasty allegations from Schreiber, who alleges the actor has been violent with her and verbally abusive in the past, according to Tmz.com.

The claims were made in legal papers filed as part of the ongoing dispute, and Patric's lawyer Fred Silberberg has now branded them "categorically untrue," adding, "These disclosures are a last gasp attempt at disparaging Gus' father... (They) are desperate comments from a desperate woman... If Ms. Schreiber is telling the truth, which she is not, then she should explain how it is that she chose to have a child with Mr. Patric, why she engaged in years of fertility treatments with him, lived with mr. Patric... (and) maintained a relationship with (him) for over 10 years."