Estate agent haart said it has seen the number of buy-to-let investors purchasing properties crash amid what it calls the government's "war on landlords".
Using data from over 100 of its branches across England and Wales, haart said buy-to-let transactions fell 40% over the year to November. There was also a 47.7% drop in the number of new landlords registering to buy.
In London, where house prices are most expensive, the falls are even more pronounced, with buy-to-let transactions down 67.7% and new landlord registrations falling by 59.2%.
"The scale of decline in buy-to-let in just twelve months is deeply worrying – landlords have clearly pulled out of the market and are unlikely to return any time soon," said Paul Smith, chief executive of haart. "However this is entirely the result of government policy, with Theresa May now picking up George Osborne's baton and proceeding to bash landlords with renewed vigour."
The government has increased taxes on landlords and the Bank of England has tightened mortgage lending rules for buy-to-let amid fears it would overheat while interest rates are at historic lows.
In April 2016, the Treasury put a 3% surcharge on top of basic stamp duty rates for purchases of property not intended to be the buyer's main residence, a move targeted at landlords. And from April 2017, a relief allowing landlords to offset their mortgage interest costs against their income tax bills will be scaled back. Smith called it a "war on landlords".
The haart data shows its average UK house price was £228,635 in November, down 1.7% over the year, though up 0.5% month-on-month. In London, the average house price hit £582,909, up 9.4% over the year and 6.2% on a monthly basis.