Just six per cent of landlords live outside the UK, compared to 13% in 2010, the analysis showed.
However, London has bucked the trend over the past year, with 12% of buy-to-let owners based overseas, up from five per cent last year.
At its peak in 2011, 20% of landlords letting homes in the capital were living abroad.
Tenants in the East Midlands are the least likely to have an international landlord, with just 3% of investors based outside the UK.
Aneisha Beveridge, analyst at Hamptons International, said: “Higher stamp duty and annual tax on enveloped dwellings (ATED) combined with a steady increase in foreign investors’ tax bills has led to a decline in foreign investment in buy to let.
“Overseas investors also saw the removal of capital gains tax exemptions in 2015.
“However over the last year, London has bucked the trend with a pickup in international landlords.
“Sterling’s depreciation, effectively offering international buyers a discount, combined with a softening London market, has helped offset the additional higher costs of owning a buy-to-let property in the capital for foreign investors.”
Rental growth slows, weighed down by London
Hampton’s research also showed rents increased by 0.2% annually in July, to sit at £964 per month.
Wales saw the highest rental growth with rents up 4.9% year-on-year, followed by the Midlands at 2.4%.
The South West and North both recorded a 0.9% rise.
Average rents in London fell for the second consecutive month, down 1.6% year-on-year.
Beveridge added: “Rental growth slowed to 0.2% across Great Britain in July.
“Falls in London were offset by higher growth in the rest of the country.
“Inner London experienced the greatest fall, with rents decreasing for the third consecutive month.”