Thicke's two eldest son, Brennan Thicke and musician Robin Thicke, filed a petition Tuesday in the Los Angeles County Superior Court after they allege that Callau disputes the prenuptial agreement she signed ahead of her marriage to the "Growing Pains" star in 2005.
"Now that Alan is dead, Tanya claims there are numerous problems with the Trust and the Prenuptial Agreement," states the Thicke son's attorney, Alex Weingarten, in the petition obtained by CNN.
The court documents also claim that Callau "threatened to make her claims fodder for 'tabloid publicity' unless the Co-Trustees agreed to participate in a mediation and succumb to her demands."
Callau's attorney, Adam F. Streisand, told CNN in a statement that Robin and Brennan's petition is "distasteful" and a "smear tactic to bully" his client.
"Tanya Thicke has never threatened to take private family matters public and she never has," the statement reads. "It is clear that Alan's sons have chosen this distasteful public smear tactic to bully Tanya, by stirring up the tabloid media, filing a bogus lawsuit, and refusing family mediation. Tanya is still grieving the death of her beloved husband and out of respect for Alan's memory intends to handle his son's false statements privately."
Brennan Thick and Robin Thicke are the co-trustees of their father's living trust. The court documents state that Thicke left each of his children shares of his ranch, 75 percent of his personal effects and 60 percent of his estate.
This leaves Callau with all of the ranch's furnishings, 25 percent of Thicke's personal effects, a $500,000 life insurance policy, the benefits from his pensions and union memberships and with 40 percent of his remaining estate. She can also live at Thicke's ranch if she maintains the property and expenses, according to court documents.
Previously, Thicke was married to actress Gloria Loring and later to Gina Tolleson with whom he had a son, Carter Thicke.
Thicke died on Dec. 13, 2016, after collapsing while playing ice hockey with Carter. His death was found to be the result of a ruptured aorta.
Thicke's son's representatives and attorney were not immediately available for comment.