Len R, a former offshore electronics engineer (who prefers to withhold his surname) and action group member from Aberdeen, had two pension funds when he had to stop work in 2005 after a series of cardiac operations.

"I didn't know much about money, my forte was engineering," he says.

Wanting to maximise income whilst protecting his wife for the future, he found an annuity advice firm online. He said: "They appeared to be independent, and they very quickly suggested I look at Rockingham, who started pushing ARM. I was told it was a 10-year term, I would be getting 10% a year with interest paid monthly, and I would have more in the pot than I started out with.

"I know if it sounds too good to be true it probably is, but everything they sent me suggested it was low-risk."

Having transferred one of his funds from Legal & General to a Sipp (self-invested pension) run by specialist Poynton York, Rockingham persuaded Mr R to transfer his other fund from Aegon into a Sipp run by Standard Life – generating a second set of commissions and fees, and with all the money in both invested in the ARM bonds.

In 2010 the payments stopped. "There was nothing I could do, I just thought how stupid I was," Mr R admits. "It really is quite desperate."