Landlords, banks and mortgage brokers are capitalising on the phenomenal resurgence of buy-to-let and now the taxman is cashing in too, with related revenues exceeding £2bn a year.

The buy-to-let tax-take is up 13pc year on year, according to the latest available data, with the number of property investors standing at a record 1.9m.

Accountants UHY Hacker Young, which produced the figures, warned that the popularity of buy-to-let has prompted HM Revenue & Customs to clamp down on the sector.

A special taskforce has been established to tackle property tax cheats, according to Hacker Young. It predicts HMRC will become “far more aggressive in pursuing undeclared rents and disposals”.

Latest data from a range of sources confirm buy-to-let is at the vanguard of the housing recovery, with existing landlords enlarging their portfolios and new investors joining the sector. They are helped by low mortgage rates, driven down in part by the Government’s Funding for Lending initiative.

Nationwide Building Society, the second largest landlord lender after Lloyds Banking Group, offers the lowest-ever landlord rate – a two-year fixed deal of just 2.49pc. The mutual says landlord lending is up 14pc over the past 12 months and “all indications show growth will continue”.

Specialist lender Paragon, which only lends to landlords, said its customers reported increased access to finance during the second quarter and a “sharp increase” in buying intention. The average yield enjoyed by a Paragon client jumped to 6.4pc in the three months to the end of June.

“Tenant demand remains very high with 93pc of landlords describing demand as growing or stable,” the lender reported.