The financial services and pensions regulators have joined forces with HMRC to issue a fresh warning against early release pension offers.
The Pensions Regulator (TPR), Financial Services Authority (FSA) and HMRC said they had each detected an increase in schemes that claim to be able to provide loans or release tax-free cash from people's pension pots before they reach age 55.
They said known transferred funds amounted to some £200m by the end of 2011.
The organisations urged individuals not to be taken in by website promotions, cold-calls or adverts encouraging them to transfer their existing occupational or private pension to a new arrangement in order to access a cash payment or loan.
These schemes usually work by transferring some of the member's pension fund into "highly risky or opaque" investment structures, frequently based overseas - with no guarantee that members will get their money back if something goes wrong.
By accessing pension savings earlier than the law permits, individuals are likely to be poorer in retirement - and can face substantial tax charges.
Victoria Holmes, case team leader at TPR, said: "These offers are typically advertised on websites or small adverts in newspapers. If the offer sounds too good to be true, it probably is.
"It may simply be a scam designed to get hold of your money. Transferring your pension to one of these questionable investment models could result in you losing your entire pension.
"Immediate financial gain may sound tempting, particularly in the current economic climate. But don't be taken in - you are likely to face substantial tax charges and will be poorer in retirement."
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