One of South Korea's best-known actresses was convicted of adultery yesterday in a high-profile case that drew fresh attention to a law banning extramarital affairs.

Ok So-ri, who was handed a suspended jail term, had lost a battle in October to have the ban declared unconstitutional.

"I would like to say I'm sorry for causing so much trouble to society," Ok said after the verdict.

A district court in Goyang, near Seoul, handed Ok a suspended eight-month jail sentence, meaning she will not serve time. Her lover received a six-month suspended term.

The sensational sex-and-celebrities case has been tabloid fodder for months, with Ok's challenge to the adultery law adding extra spice.

Last year, Ok acknowledged in a news conference that she had had an affair with an opera singer who was a friend of her husband in 2006. She stressed the affair was a result of her loveless marriage to actor Park Chul.

The court appeared to show some sympathy.

"Though the fact of adultery should be criticised, the court issued this ruling taking into account that husband Park Chul's responsibility was not small," the court said.

Ok also "suffered mental pains" from the invasion of her privacy, the court said.

Ok earlier this year filed a petition to have the adultery ban ruled an unconstitutional invasion of privacy. However, in October, the constitutional court upheld the ban, part of South Korea's 55-year-old criminal code.

Despite decades of Western influence, South Korea remains deeply conservative. Those convicted under the adultery law face prison sentences of up to two years, though few serve time.

Supporters of the ban say it promotes monogamy and keeps families intact. Opponents say it violates privacy.

Many Muslim nations have anti-adultery laws. Taiwan, Austria, Switzerland and some US states also have laws prohibiting extramarital affairs.