Alan Thicke's sons take his widow to court over estate

— -- Alan Thicke's sons, Robin and Brennan Thicke, are taking their father's widow to court in a battle over his multi-million dollar estate.

In a petition filed Tuesday in Los Angeles County Superior Court and obtained by ABC News, Robin and Brennan Thicke, who are co-trustees of their father's living trust, say they have been "left with no choice but to bring this petition to honor the memory of their father, protect his legacy, and prevent his testamentary intentions from being undermined by avarice and overreaching of his third wife, Tanya Callau."

Alan Thicke, who was best known for his starring role in the 1980s sitcom "Growing Pains," died last December at age 69. He suffered a ruptured aorta while playing ice hockey with his youngest son, Carter.

His two older sons claim in their petition that Callau, a Bolivian-born actress who goes by Tanya Callau Thicke, is insisting that a prenuptial agreement that she signed just before their 2005 marriage is no longer valid and that she is entitled to a larger share of Thicke's estate.

"The Thickes are asking the court for instructions concerning the extent to which the Trust's property is the actor's separate property and whether Callau Thicke's challenge to the prenup is barred because she waived her community property rights when signing it," their attorney, Alex Weingarten, said in a statement to ABC News.

According to the documents, Thicke left each of his three children equal shares in his ranch in Carpinteria, California, 75 percent of his personal effects and 60 percent of his remaining estate. He left Callau Thicke 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 of his remaining estate. He also stated that she could live at the ranch, as long as she maintained the property and expenses.

Since Thicke's death, Weingarten said in the claim, Callau Thicke has found "numerous problems" with the trust and prenuptial agreement.

He also stated that Thicke's wife 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."

"My clients made every effort to resolve this without the need for going to court," Weingarten said in the statement to ABC News. "The only thing they care about is protecting the legacy of their father and honoring his intentions. That is exactly what we are going to do."

Callau Thicke's attorney has refuted the sons' claims.

In a statement to ABC News, her lawyer said she "has never threatened to take private family matters public and she never has. 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."

The statement added, "Tanya is still grieving the death of her beloved husband and out of respect for Alan’s memory intends to handle his sons' false statements privately."