One of Hollywood's most endearing love affairs appears to be unraveling.

Michael Douglas and Catherine Zeta-Jones separated after 13 years of marriage, according to E! News.

"Catherine and Michael are taking some time apart to evaluate and work on their marriage," Zeta-Jones' publicist, Cece Yorke told USA TODAY in a statement. "There will be no further comment."

According to People, Douglas and Zeta-Jones, both Oscar winners, have in recent months vacationed separately and are reportedly living apart. Douglas, 68, and Zeta-Jones, 43, have not been photographed together since April, when the couple attended a gala event at Manhattan's Lincoln Center. According to a few media reports, Douglas has moved out their family home. 

Douglas has reportedly been relaxing on a yacht and playing golf in Sardinia, the Daily Mail reported. 

Neither star has filed for divorce nor moved toward a legal separation.

According to E! News, the couple's marriage has been strained due to the hardships both have suffered in recent years. Douglas successfully battled throat cancer in 2010, while Zeta-Jones has struggled with a bipolar disorder for which she's twice sought treatment in 2011 and again in April of this year.

"The stress has taken a toll on their marriage," a friend told the magazine.

Most recently, Douglas' comments about HPV [human papillomavirus] possibly causing his cancer are said to have not gone over well with Zeta-Jones. He issued a statement clarifying that he was not saying he got it from her. 

But according to People, the pair is still hoping to patch things up so reconciliation is not out of the question.

"They want the best for their kids, no matter what happens," said a family friend.

The couple first met in 1998 at the Deauville Film Festival in France and began dating the following year. They became engaged on New Year's Eve of 1999 and co-starred in the 2000 release "Traffic." Douglas and Zeta-Jones tied the knot in 2000 in a fairy tale wedding at Manhattan's Plaza Hotel. The Oscar-nominated couple, have two children together,  Dylan 13, and Carys, 10.

Douglas reportedly opted for a prenuptial agreement when he married Zeta-Jones, after learning from his first marriage; one that resulted in him shelling out $45 million in a divorce settlement to ex-wife Diandra Luker.