Investors in storage pods buy a long lease with the theory that people will always need storage. However, these investments are unregulated, and there is little evidence that the high rental yields promised have ever materialised.

The SFO has launched an investigation into Capita Oak Pension and Henley Retirement Benefit schemes, Self-Invested Personal Pensions (SIPPs) as well as other investment schemes.

It will also look at Westminster Pension Scheme and Trafalgar Multi Asset fund which invested in other products.

Over 1,000 investors are believed to have been affected by alleged fraud, including those who invested their pension funds, with estimates of the total invested at more than £120m.

Anyone who has invested in these schemes between 2011 and 2017 is asked to complete the SFO’s investor questionnaire to help it gather more information.

Kate Smith, head of pensions at Aegon, said the estimated number of people affected could be “just the tip of the iceberg”.

“The SFO investigation into storage pod investment schemes is a timely reminder that unregulated unusual investments at home or abroad come with a high risk that people could lose all their hard-earned pension and other savings. Savers must be on their guard. Promises of high returns or financial inducements are often scams and people falling for this type of investment scam run the risk of their lifetime’s savings being lost in a matter of seconds.

“The SFO suspect that over a 1,000 people and a vast sum of £120m could be affected and are asking people who have paid into storage pod investment schemes between 2011 and 2017 to complete an online questionnaire. Unfortunately this may prove to be the tip of the iceberg with potentially thousands more yet to discover they’ve lost money.”