Alan Thicke's sons are taking his widow Tanya Callau to court

Two of Alan Thicke's sons are taking the late actor's window, Tanya Callau, to court over a prenup to protect the Growing Pains star's estate.

People reported that documents were filed on Tuesday, May 16, by Thicke's sons, Robin and Brennan. The docs allege that Callau is saying that a prenup she and their father signed before they were married in 2005 is not valid.

RELATED: Carter Thicke reveals which celebrity helped him through his father Alan Thicke’s death

Thicke reportedly left his sons “(in equal shares): ownership of the Carpinteria, California ranch" as well as  "75 percent of his personal effects and 60 percent of his remaining estate.” Callau was left with  “all of the Ranch’s furnishings, 25 percent of his personal effects, a $500,000 life insurance policy, all of his death benefits from pensions and union memberships … and 40 percent share of his remaining estate. Alan also provided that Tanya may live in the Ranch after his death so long as she maintains the property and expenses.”

But now, after apparently never having an issue with the prenup before, Callau is claiming that the agreement is invalid.

“Tanya asserts that there is no chance the ‘Prenup’ could withstand legal challenge and that she has very significant community rights in the Trust’s assets and rights of reimbursement with respect to improvements to the Ranch. Tanya also claims ‘Marvin rights’ asserting that she had to forego opportunities to pursue and advance her own career in order to support Alan and be his companion and partner, including raising Carter,” attorney Alex Weingarten wrote in the petition, adding that Callau has “threatened to make her claims fodder for ‘tabloid publicity’ unless the Co-Trustees agreed to participate in a mediation and succumb to her demands.”

As we reported, Thicke died suddenly while playing hockey with his son, Carter, last December following a heart attack at the age of 69. The official cause of death later confirmed that the actor died from a ruptured aorta.