SEOUL, S.Korea - Nearly four out of every 10 female entertainers in South Korea face unwanted sexual pressure, a survey showed Monday.

The survey of actresses, singers and TV personalities was conducted by opposition party lawmaker Byun Jae-Il and made public during a parliamentary session.

Some 25 percent said they had experienced unwanted physical contact, while 12.5 percent said they had been forced or requested to provide sexual favours in return for money or to advance their career.

The survey showed 43.8 percent were forced to drink with high-ranking figures in the entertainment industry, while 37.5 percent have experienced violence or abusive language at such gatherings.

Yonhap news agency quoted Byun as saying the exploitation of entertainers, especially young women, by some agents "has gone beyond the limit".

He called for swift government measures saying "this is not an issue to be left to the self-regulatory aspect of the market".

Agents and managers often pressure actresses to have sex with them while being videotaped, and later use the film as blackmail to prevent them from skipping to bigger firms, Yonhap said.

In March actress Jang Ja-Yeon committed suicide after suggesting she had been forced to have sex with influential figures in the entertainment and media industry to promote her career.

She left a note reading: "I am a powerless young actress who can't fix what is so evidently wrong."