NSW Labor MP David Campbell has resigned as the state's Minister for Transport and Roads.

Mr Campbell has been accused of using a taxpayer funded government car to visit a gay sex club in the state Premier's eastern suburbs electorate.

According to Seven, Mr Campbell visited the gay club, Ken's at Kensington on Anzac Parade, Tuesday night in Premier Kristina Keneally's electorate of Heffron for two hours.

The station then showed footage of a man who appeared to be Mr Campbell, wearing a white business shirt and dark trousers but no jacket.

The man emerged from a doorway into a street and a set of ascending stairs could be seen clearly behind him.

The man walks along the ill-lit street, passes a corrugated iron fence before emerging from the darkness to get into a white Holden sedan.

Comment is being sought from Ms Keneally.

Mr Campbell resigned as the state's Minister for Transport and Roads, citing personal reasons.

"I have resigned as minister for Transport and Roads for personal reasons, not for any reasons relating to my ministerial duties,'' he said in a statement today.

"I apologise to my wife, family, colleagues, staff and the community for letting them down.

"This will be a very difficult time for my family and friends and I ask for their privacy to be respected."

Mr Campbell said he would remain in Parliament as the member for Keira, on the state's south coast.

"I am incredibly proud of my achievements while serving as minister for Transport, Roads, Police, Small Business, the Illawarra, Regional Development and Water Utilities," Mr Campbell said in the brief statement.

A spokesman for Opposition Leader Barry O'Farrell said the Opposition would not be commenting on Mr Campbell's resignation.