A fish supplier netted almost £1 million by selling non-existent fish to imaginary buyers.

Christopher Bish sent out more than 4,500 ghost invoices to stave off cash problems at his firm, Jelfish Ltd.

He sent the bills to a factoring company - an agency which buys unpaid invoices in exchange for a commission on their total value.

He then set up a web of fake customer addresses - using the details of part-time workers - to ensure the firm did not become suspicious. It was only after a tip-off that the company became aware of the scam.

Hove Crown Court heard invoices worth £5.5 million had been submitted and the factoring firm was still owed more than £700,000.

Bish, 46, of Northease Gardens, Hove, was yesterday jailed for 21 months after admitting fraudulent trading between November 1998 and November 2000.

Peter Gower, prosecuting, said Bish was the mastermind behind the fraud. He said: "These invoices were entirely bogus.

"The businesses to which they were made out for the most part did not exist."

Bish was a director of Jelfish, of Lower Goods Yard, Trafalgar Street, Brighton, which he set up with his brother Michael in 1994. At its height, the company had a turnover of more than £700,000 a year.

Mr Gower said Christopher Bish took control of the financial side of the company while his brother dealt with buying and preparing the fish.

He said: "Over the period covered by the indictment Jelfish submitted to its factoring company, Singer and Friedlander, over 4,500 invoices with a face value of more than £5.5 million.

"When the fraud came to light as the result of anonymous letters sent to the directors of Singer, the amount owed to them was just under £1 million, of which £705,634 is still owed.

"Much of the company's invoices were factored to Singer. Upon receipt of an invoice Singer would advance to Jelfish the face value of the invoice.

"Singer would then seek to recover from Jelfish's clients the full value of the debt. In order to ensure the fraud went undetected, Christopher Bish set up a network of contact addresses and phone numbers for each of the bogus companies.

"This was to ensure that when Singer carried out checks in order to verify from these "customers" the amounts they owed, the appropriate response could be given. Christopher Bish masterminded the fraud."

Singer's credit controllers became concerned in July 2000, having became suspicious when a contact number given for one of the businesses did not check out.

Keith Edwards, Singer's managing director, and his successor Paul Gee later visited addresses in Brighton falsely given by Bish as those of companies owing money to Jelfish.

Mr Gower said: "In November, 2000, a number of Singer directors were sent an anonymous letter. It purported to be sent by a disaffected former employee of Jelfish and said at least seven of the Jelfish customers were non-existent."

The court was told Jelfish had been losing money for some time.

Rob Hall, defending, said: "Now that this has been investigated he is bankrupt, has lost all his assets and is in ill health. He has expressed remorse and shame."

Bish was disqualified from being a company director for six years.