Along with the City of London Police, the FSA executed search warrants on nine premises in Kent and Greater London. Nobody has been charged at this stage in connection with the FSA's investigation, which is ongoing, the regulator said in a statement. It declined further comment.

Land banking refers to the practice of persons selling plots in land they claim will receive planning permission for development, such as for housing and commercial use. Additionally, the FSA is understood to be concerned that such parcels of land are being held in investment portfolios without proper authorisation and controls. In some cases, parcels of land are sold to people who are told - falsely - that planning consent has been given or will be given.

It is understood that some of the people who have bought investments in land banking deals are wealthy individuals.

The FSA does not regulate land as an investment but it does regulate collective investment schemes, including those concerning land.