Catherine Zeta-Jones and Michael Douglas take a break from each other 'to work on their marriage'

Michael Douglas and Catherine Zeta-Jones on 22 April 2013 (Getty Images)

Academy Award-winning actors Catherine Zeta-Jones and Michael Douglas are "taking some time apart to evaluate and work on their marriage", a statement released by her publicist said.

The Hollywood couple, who have not been photographed together since April, have apparently decided to take a break from one another after 13 years of marriage.

Neither Douglas or Zeta-Jones have sought to legally separate or divorce. Douglas' publicist Allen Burry echoed Zeta-Jones' statement and declined to comment further.

Douglas, 68, is currently on holiday off the coast of Sardinia. Zeta-Jones, 43, is at home in New York with their two children, son Dylan, 12, and 10-year-old daughter Carys.

The pair, who married at Manhattan’s Plaza Hotel in 2000, have come under increasing pressure in recent years.

An unnamed ‘friend’ told People.com that the impact of ill health on both sides, plus Douglas’ son Cameron’s imprisonment on drugs charges, were contributing factors: "The stress has taken a toll on their marriage.”

Douglas, who has won two Oscars and four Golden Globes during his 40-year career, was diagnosed with Stage Four throat cancer in August 2010 but got the all-clear a year later.

Welsh-born Zeta-Jones has spoken candidly recently about her battle with bipolar 2 disorder. The actor admitted herself to hospital for “maintenance” treatment in April.

She also spent five days in a rehabilitation clinic 2011 when her condition worsened – something she resulted from the strain of Douglas’ cancer treatment.

“I'm not the kind of person who likes to shout out my personal issues from the rooftops but with my bipolar becoming public, I hope fellow sufferers will know it is completely controllable,” Zeta-Jones told US InStyle magazine last year.

“I hope I can help remove any stigma attached to it, and that those who don't have it under control will seek help with all that is available to treat it.”

Douglas came under fire in June for reportedly blaming the development of his cancer on oral sex – something he later denied saying during a newspaper interview.

Douglas was quoted in the Guardian denying that years of smoking and drinking were behind his near-fatal brush with cancer: "No, because without wanting to get too specific this particular cancer is caused by HPV [Human papillomavirus] which actually comes about from cunnilingus."

"I did worry if the stress caused by my son's incarceration didn't help trigger it. But yeah, it's a sexually transmitted disease that causes cancer. And if you have it, cunnilingus is also the best cure for it."

But a statement from his publicist later retracted the remarks, despite the Guardian releasing audio files in which he appears to say it.

Zeta-Jones spoke publicly about her marriage and treatment for bipolar disorder earlier this year. She said the experience had helped her to gain appreciation for life and had strengthened her marriage.

“You find out who you really are and who you are married to. You find things inside yourself you never imagined were there,” she said.

Swansea native Zeta-Jones began her career as a stage actor before gaining fame on ITV’s The Darling Buds of May and moving to Hollywood where she was cast in The Mask of Zorro, Traffic and Entrapment.

She won the best supporting actress Oscar for her performance in 2002's Chicago and was made a CBE in 2011.

New Jersey-born Douglas, the son of Hollywood star Kirk, is probably best known for playing Gordon Gekko in the Wall Street films.