Marcel Sulc, 40, who has built a huge property portfolio, has been accused of using intimidation and shady business practices to snatch away flats in blocks where he has bought the freehold.

This newspaper's investigation has led to a call from Michael Foster, the Labour MP for Hastings in East Sussex, where Sulc is based, for emergency meetings with the police and the local council.

'Over the last few months serious local concerns over the activities of Marcel Sulc have been brought to my attention,' Foster said.

'Many of the allegations are now of criminal activity.'

The Observer has further learnt that at least one of Sulc's companies is now under investigation by the Department of Trade and Industry for alleged breaches of company law. Details of his other activities have been passed to the police.

Much of the fortune Sulc has made though 'snatching' homes has been invested in larger properties such as Sussex House, a former old people's home on the seafront at St Leonards which Sulc bought for around £500,000 and is converting into flats.

One of his employees told The Observer that soon after the purchase, Sulc discussed the idea of obtaining mortgages on the flats for bogus buyers so that he could effectively sell each property more than once.

That plan did not go ahead, but it would not have been the first time Sulc had been involved in such activity. He was convicted in the Nineties for his part in a major mortgage fraud. His conviction was quashed on appeal due to a legal loophole which has since been closed.

More recently, Sulc came under renewed police scrutiny during a dispute over a joint venture at the run-down Regents Hotel, on the Hastings seafront.

There were several arson attacks on the building and a chimney breast was deliberately pulled down, causing structural damage. Sulc was questioned by police over the chimney collapse.

Sulc refused to comment.