Paula Patton claims Robin Thicke threatened to have her arrested for kidnapping their six-year-old son, Julian.

Paula Patton

Paula Patton

The 41-year-old actress, who is currently embroiled in a bitter custody battle with her ex-husband, alleges in new court documents, obtained by gossip website TMZ.com, that he "willfully, intentionally, and wrongfully changed/fabricated a Court Order specifying custodial timeshare of the couple's minor child" and "threatened to have [Paula] arrested for kidnapping premised upon the false and fraudulent court order" shortly before she was awarded temporary sole custody in January.

But a source close to 'Blurred Lines' hitmaker Robin, 39, insists they came to a custody agreement in February 2015 with a mediator and documented the details in notarized, private papers.

The insider told PEOPLE.com: "The document read exactly as it did on Feb. 4, 2015 when both parties agreed and signed, and there was nothing changed on that document."

The actress is also accusing Robin and his team of engaging "in conduct specifically designed to influence the outcome of the DCFS investigation," claiming the singer "took a DCFS case worker out for an expensive sushi dinner while DCFS was actively investigating allegations of abuse perpetrated by Mr. Thicke."

But the source close to Robin says the dinner, which took place at Nobu in Los Angeles, was merely where he took Julian during one of his supervised visits and the DCFS worker did not sit at their table.

A judge granted Paula sole custody of Julian after she alleged in court documents that her ex physically abused her, was unfaithful and struggles with drug and alcohol addictions.

And under a temporary restraining order taken out against him, Robin is also required to stay 100 yards away from Paula, her mother and Julian outside of the pre-arranged visitation hours.

The duo, who split in 2015 after 21 years together, are due to appear in court later today (24.02.17).