TAIPEI (AFP) - A Taiwanese rights activist and outspoken critic of his government's attempts to seek closer ties with Beijing criticised the Chinese authorities after he was denied entry to Hong Kong on Sunday.

Mr Chen Wei-ting, a key figure in an unprecedented student-led protest occupation of Taiwan's Parliament earlier this year, had planned to attend a mass rally on Tuesday in Hong Kong in support of greater democracy there.

But he said he was immediately taken away and questioned by officials upon arrival at Hong Kong airport on Sunday afternoon. "They told me I could not enter Hong Kong due to 'political factors'," Mr Chen told AFP, adding that he was questioned for about an hour before being sent back to Taiwan.

Mr Chen said he had also planned to visit some friends organising an unofficial pro-democracy referendum in Hong Kong, reciprocating their support for the three-week-long Taiwanese protests against a proposed services trade pact with China.

"They don't want me to enter Hong Kong because they feared the merging of democracy movements with Taiwan," said Mr Chen, who flew to Hong Kong on a travel document issued specially for Taiwanese by the Chinese authorities.

But Mr Chen said some other supporters of Taiwan's democracy movements had managed to get into Hong Kong to attend the rally on Tuesday.

Organisers expect it to be the largest since Hong Kong's handover with upwards of 500,000 people.

Hong Kong's immigration department said it would not comment on individual cases.