Describing the move as free advertising, they claimed it had affected the fairness of the by-election for the Regional Council seat, and called for the cost to be included in Mr Cheung's election expenses.

But Mr Cheung, the Democratic Alliance for the Betterment of Hong Kong candidate, said such allegations were another dirty trick, and the paper's publicity campaign was nothing to do with him.

Thousands of copies of the pro-China paper were handed out free in Sai Kung and Tseung Kwan O last week, carrying features, news stories and pictures on Mr Cheung.

Independent Wong Wah-keung said: ''If free newspaper circulation is used as a promotion in such a small by-election, then what will they do in the 1995 Legco elections? Will they hand out renminbi?'' Another independent Wong Shui-san said: ''This activity should be counted in election expenses and the Government should monitor such cases.'' Mr Cheung said: ''Free circulation is a common part of the newspaper business. They [the other candidates] are trying to manufacture a story. They should concentrate on how to serve the residents of the area instead.'' Today's by-election has also been marred by other allegations of dirty tricks, including the tearing down of candidates' posters, unsavoury rumours spread about some participants, and a candidate's assistant switching sides.

One candidate said he had asked the ICAC to investigate after he was approached by a man offering him 200 votes in exchange for money.

''It may have been an attempt to try and trap me,'' he said. ''I have sent a letter to the ICAC and they will follow it up after the election.''