The film crew behind a documentary on Nicholas Hoogstraten has revealed how prison failed to mellow the property tycoon .

Mr Hoogstraten owned more than 400 homes in Brighton and Hove at the height of his power and remains one of the country's richest businessmen.

He was followed for four months for the Hotel Hoogstraten documentary which features interviews with his inner circle at his base, the Courtlands Hotel in The Drive, Hove.

The millionaire is filmed proudly holding a pen he stole from his lawyer in a scene shot by director Saul Dibb for the Underground Britain television series.

Alastair Cook, Underground Britain series producer, said: "Hoogstraten is interested in the pursuit of wealth for the accumulation of wealth and that drive has not mellowed at all.

"We wanted an insight into a complex individual operating on the edge of mainstream legality and morality but it is difficult to know how much is bravado and how much is real threats and intimidation."

The millionaire landlord is quizzed on camera about his family, business and the pursuit of money after Mr Dibb began visiting him in Hove last November.

Mr Hoogstraten told the BBC: "I am not interested in spending money.

"I never have been - spending money would be the opposite to enjoying myself.

"What else is one supposed to do other than stopping people f***ing me and stealing my money?"

Scenes shot inside the hotel reveal how his closest allies are among the staff but the film indicates that even they are denied preferential treatment by the businessman who is shown refusing to give a former girlfriend a soft drink while she is at work.

Mr Hoogstraten's fascination with money is revealed in an interview by the mother of two of his children, Caroline Williams, manager at the Courtlands Hotel.

She said: "Nicholas is straight and it is only when people try to have one over on him when he goes the other way.

"Everything boils down to money and if anyone owes him money he will try to get it by whatever means.

"It is an obsession with wealth and properties and accumulation of it and there never seems to be a time when it is enough."

Hoogstraten was jailed for ten years in 2002 for the manslaughter of another Brighton landlord, Mohammed Raja, 62.

Mr Raja was shot dead by two men identified at an Old Bailey trial as Hoogstraten henchmen. But Hoogstraten's conviction was later quashed by the Court of Appeal.

Mr Dibb, who also filmed the critically acclaimed Bullet Boy about Britain's burgeoning gun culture, occasionally found himself confronted with his interviewee's demanding nature.

Looking around a flat for signs of mismanagement, Mr Hoogstraten orders Mr Dibb to turn the cameras on fungus growing up through the floor.

When Dibb explains it is his decision where the camera goes, Mr Hoogstraten tells the director to play "quid pro quo" and record the damage for his legal case in exchange for the access to his business empire.

Mr Hoogstraten said: "It is difficult to retain morality in a world which is immoral and amoral.

"I don't believe money brings happiness.

"The ultimate power is what one is prepared to do and I am prepared to do whatever is necessary."