Landlords who sold their rental property last year did so for an average £86,651 more than they paid for it, having owned the home for an average of 8.7 years.

In London, the capital gain was much more – with landlords making an average £253,981, according to date from Countrywide’s research team.

While these capital appreciation figures are impressive they are also actually slightly lower than comparable gains would have been for owner occupiers selling properties in 2017, the team says.

Owner-occupiers made on average £92,886, because on average they owned the property for nine full years.

Johnny Morris, research director at Countrywide, says: “House price growth has driven investor gains. Landlords selling in 2017 owned their homes for nearly nine years and in eight of them house prices have risen.

“Even in areas where price growth has lagged behind most landlords have made a profit from rising prices.”

Meanwhile other data from Countrywide shows that the average rent of a new let rose to £954 per calendar month across Britain last month.

This means the rate of annual rental growth has slowed to 1.5 per cent, down from 2.4 per cent the previous month.