Nearly 40% of all homes sold under Right To Buy in England have gone on to become buy to let investment properties.
Research by social housing magazine Inside Housing, using data gathered through Freedom of Information requests, shows that 91 councils suggest a combined 127,762 council maisonettes and flats have been sold since the Thatcher government introduced Right to Buy in 1980.
However, some 48,000 leaseholders are registered as living away - suggesting they are not owner occupiers so, are probably, letting the properties.
It is not clear home many of the Right to Buy homes were sold directly to tenants who became landlords to let them out, or sold initially to tenants who acted as owner occupiers and then sold the units on as investment properties at a later date.
In six local authority areas - Milton Keynes, Stevenage, Blackpool, Corby, South Kesteven and Kingston - over 50% of Right to Buy properties are believed to be privately let.
The current government is expected to unveil legislation on extending Right to Buy, and its controversial discounts for existing occupiers, to around 1.3m housing association tenants.