The Only Way Is Essex star Lewis Bloor used a fake name to con people in a £3 million diamond scam, a court has heard.

Bloor, 31, who joined the cast of the ITV2 reality show for three years from 2013, allegedly posed as “Thomas Harkin” to dupe investors into buying the coloured stones at a 600% mark-up.

Around 200 people, many of whom were elderly, were allegedly fleeced of more than £3 million by fraudsters working for two firms, Imperial Assets Solutions (IAS) and Henderson & Forbes.

Southwark Crown Court heard on Tuesday that Bloor was paid £150,000, with some of the money paid on to others, by IAS, before leaving to pursue his television career.

The court heard that another employee, Max Potter, 25, told a friend in messages: “They have all got great big Rolexes and Porsche jeeps,” and said his cousin, who ran the company, “is 28 and he’s a millionaire”.

One alleged victim, Michael Williams, described Bloor as having a “very persistent style” which “subtly put pressure on me”, the court heard.

Prosecutor David Durose QC said: “Mr Williams said he was made to feel that he was buying a valuable item at a fair market price which would quickly go up in value with little risk.”

He said Mr Williams bought a stone for £5,978.70, while Bloor was paid £896.81, or exactly 15% of the investment sum.

“These diamonds were marked up by five or six times so that’s probably about the sort of figure that IAS would have actually paid for the diamond,” he said.

“Fifteen per cent of the investment disappeared straight away, was not going anywhere near the price of the payment, and Mr Bloor knew that, of course, because he received that money.”

Bloor, of Buckhurst Hill, Essex, denies conspiracy to defraud between May 7 2013 and July 1 2014.

He is on trial alongside Joseph Jordan, 29, from Waltham Cross, Hertfordshire, George Walters, 29, from Beckenham, in Kent, Potter, of Enfield, Middlesex, Nathan Wilson, 28, of Brentwood, Essex, and Simon Akbari, 27, from Loughton, Essex, who also deny the charge.

Both of the firms involved purported to be specialist brokers for people wanting to buy or sell investment grade stones, the court heard.

People were cold-called and sent glossy brochures with quotations from De Beers and office addresses in a prestigious Canary Wharf skyscraper and Antwerp, the worldwide home of the diamond trade, the court heard.

They were sold the coloured diamonds as a genuine investment which would increase in value, it was heard. But the stones, which were bought from a wholesaler and sold on with a mark-up of around 600%, could never have been a legitimate investment, it is alleged.

Bloor was said to be one of those with a “more central role in the fraud”, who sent scripts to those making the calls, the court heard.

Two such documents found in his home offered investors the “exciting opportunity” to buy rare coloured diamonds bought from the Argyle mine in Australia, which were about to “shoot up in value”, the court was told.

And claims were made of 21% returns in the previous year with a level of “exclusivity” suggested by reference to “two or three projects a year”, the court heard.

“In reality, IAS did not have two or three projects a year, but rather sold over 100 diamonds very quickly in six months,” said the prosecutor.

“Every IAS client who has given a witness statement lost their money and there is no evidence of any client making money.”

Mr Durose said the alleged fraudsters tried to persuade their victims to invest as much as they could, with one, Peter Cooke, encouraged to re-mortgage his house and borrow money from family and friends.

“It was only when it was clear to the fraudsters that they had rinsed their victims dry that they would stop contacting them,” he added.

The court heard a total of 321 diamonds were sold by the two firms, of which 275 were seized by police from a bonded warehouse where they were stored in Geneva, Switzerland, and valued at “remarkably low prices”.

The trial continues on Wednesday.