The City watchdog could take over regulation of certain personal pension schemes under moves being considered by the Government.
The Treasury plans to issue a consultation on whether Self-Invested Personal Pensions ( Sipps) should be brought under the remit of the Financial Services Authority.
The rules governing Sipps, which are currently unregulated, are due to change next April, enabling their holders to invest in everything from residential property to fine wine and antiques.
The consultation on whether to bring Sipps within the scope of the FSA is part of a wider exercise looking at reforming the eligibility rules governing which companies could set up tax-privileged pension schemes.
As part of this, the Treasury will look at regulating who sets up and runs pension schemes, which could lead to Sipps and other nonoccupational schemes being brought within the FSA's remit.
A Treasury spokesman said: "If implemented, this could have the effect of bringing Sipps and all other nonoccupational pension schemes within the scope of FSA regulation.
"However, this will not be the only option for consultation, and no decision will be taken until responses to the consultation have been received and thoroughly considered."
Even if the Treasury did decide Sipps should be regulated by the FSA it would be some time before this took effect.
An FSA spokeswoman said Sipps did come within its regulatory remit, it would carry out consultation which "could take anything from two to three months to two years, depending on the nature of the regulation and responses".
Commentators have predicted the changes could lead to a flood of people putting their second homes or buytolet properties within pensions to benefit from the tax relief on offer.
But the Treasury said the changes would not create new incentives. A spokesman added that if someone wanted to put an existing second home into their pension they would have to sell it to a trust, meaning they would incur capital gains and stamp duty costs.