Prosecutors had been seeking 18 months in jail for Ok So Ri who admitted to having an affair with a singer. The suburban Seoul court sentenced her to eight months in prison but she avoided jail because it was suspended for two years.

South Korean enacted its adultery law more than 50 years ago to protect women who had few rights in a male-dominated society but critics say now it is a draconian measure no longer fit for a country with an advanced civil and family court system.

In October, Ok lost a case she had brought to the country's Constitutional Court, which ruled against the actress and said society would be harmed if it overturned the law that can send a person to jail for up to two years for adultery.

Ok's lawyers said in a petition to the Constitutional Court: 'The adultery law ... has degenerated into a means of revenge by the spouse, rather than a means of saving a marriage.'

It is rare for courts to jail adulterers but that does not stop several thousand angry spouses from filing criminal complaints each year.

Critics have said a better compromise might be to allow spouses just to sue for compensation in civil court. -- AFP