A police spokeswoman said Jackson, an Australian, fell from the fourth-floor roof about 4am. His empty wine glass was found on the roof. She said Jackson's Gurkha domestic helper heard the main door close at 3am, thought his boss had gone out and investigated no further.

Police said no suicide note had been found and it was unclear whether Jackson had fallen accidentally or jumped.

Central divisional commander Superintendent Chau Ping-sun said there were no suspicious circumstances.

In his 13 years in Hong Kong, the flamboyant Jackson had become synonymous with exciting and innovative interior design. Architects Denton Corker Marshall brought him to Hong Kong from Melbourne to run their design division.

'We wouldn't have brought him up if he wasn't extremely talented,' a former colleague said.

Clients included tycoon Richard Li Tzar-kai and Alasdair Morrison, former managing director of Jardine Matheson. 'His special talent was bridging the gap between Chinese and expatriate tastes,' said furniture designer Garrison Rousseau, a longtime friend, speaking from the Philippines.

Jackson's death has baffled friends. Raju Harilela, executive director of the Harilela Strategic Group, said: 'He was not depressed, he was busy, doing a hotel for Swire at Tung Chung, as well as new housing projects at Shouson Hill and Black's Link. His work was going well.'

Jackson's secretary, Wendy Lo Wai-ha, one of his 12 employees at Simon Jackson and Associates in Central, the firm he started after leaving Denton Corker Marshall, described him as 'a very good boss, very good to clients and friends, a very good man'.

Mr Harilela said he spoke for Jackson's friends, having been on the phone to many of them since hearing the news. 'We are devastated. We loved him very much, he was a wonderful soul. He was supportive, kind, loving. He gave so much. He touched us all.'

On a personal level, the past few years had been difficult for Jackson. In July 1999 he was beaten and robbed of jewellery worth $800,000 when three men burgled his flat. He felt deeply betrayed, he told friends, when it emerged his two Filipino houseboys were involved. 'He was so afraid he hired Gurkhas after that,' Mr Harilela said. 'But although he felt betrayed, he said he would get over it and he did.'

He continued: 'I don't understand this. What he's done is very uncharacteristic. I had dinner with him a few weeks ago and he was feeling brave and courageous. I can hardly believe he did his.'

But Mr Rousseau said he felt Jackson, who was a homosexual, never fully recovered from the trauma of the robbery.

'I think he felt alone and unloved. We could all love him as a friend, but he never found real love in Hong Kong. He was always lonely here. He was very petite, so Chinese guys didn't like him,' Mr Rousseau said.

Jackson had been 'very troubled with depression over the last few years and at one point he was doing a lot of cocaine', he added.