Hong Kong  - The Olympic Torch was Wednesday due to return to Chinese soil at the end of its troubled world tour as more activists were denied entry to Hong Kong ahead of its arrival.

The torch was due to reach the former British colony from Vietnam ahead of Friday's relay through the city which will be closely watched for protests and demonstrations over Tibet.

Hong Kong is the only place in China apart from Macau where anti-China demonstrations are allowed, thanks to the territory's 'one country, two systems' arrangement with Beijing.

However, the city's Beijing-appointed administration has taken a hard line against protestors so far, expelling Danish sculptor and human rights activist Jens Galschiot and his sons when they arrived Saturday to take part in anti-China protests.

Four more activists have also been refused entry at Hong Kong international airport, it emerged Thursday, including two members of the Students for Free Tibet movement and the London-based spokesman for the Free Tibet Campaign, Matt Whitticase.

In a statement sent to Deutsche Presse-Agentur dpa after he was ordered to return to the UK, Whitticase said: "Everywhere one looks, China is slamming the door in the face of free expression.

"Tourists are being refused entry to Tibet, journalists are being prevented from reporting freely from Tibet, Sichuan, Gansu and Qinghai and now I have been denied entry to Hong Kong.

"Denying me entry not only represents a slap in the face for the concept of 'one country, two systems'; it also demonstrates yet again that China clearly has much to hide in Tibet."

Actress and Dafur activist Mia Farrow is due to arrive in Hong Kong Thursday and criticize China for failing to stop genocide in the Sudan in a speech at the Foreign Correspondents Club on Friday.

The Immigration Department on Wednesday refused to confirm or deny claims that Farrow too would be denied entry when she landed in Hong Kong.

Some 3,000 police are due to guard the 30-kilometre torch relay route through Hong Kong from 10 am Friday.

Singer-actor Jacky Cheung, windsurfing gold medallist Lee Lai-shan and tycoon heir Victor Li will be among the runners. (dpa)