The Serious Fraud Office has launched an investigation into a fund controlled by a British financier alleged to have defrauded expatriates in Mallorca of £20m.

John Hirst’s firm, Gilher Inc, “targeted British nationals and other expatriates” on the island with a scheme that promised “guaranteed” returns of 20%, said the SFO. When the 58-year-old abruptly left the island this summer investors contacted the SFO. It is thought that more than 150 people, most of them British, are affected.

A victim support group has been set up on the island by Jan Fitzgerald, 65, who is originally from Leeds. Forty victims, most of them elderly, have joined. Fitzgerald, who invested €80,000 (£71,000) with Hirst over eight years, said the fraud will “destroy lives” on the Spanish island.

“I am devastated. Last Friday night I said that I wanted to commit suicide but I have decided to dust myself off and fight this. I suspect there is not a lot of money left but we’ll fight for it,” she said.

Hirst, who ran the fund for seven years while living on the island, was a well-known figure in the expat community and was a keen cricketer. Most of his clients are thought to have been friends or social acquaintances. It is understood he has returned to Britain but has not contacted the authorities. He told investors he had been diagnosed with leukaemia.

The SFO’s investigation is focused on Gilher Inc, which is registered in Cyprus and the Seychelles and controlled by Hirst.

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