The highest number of 'risky' mortgages issued during 2015 was in South West London, according to new analysis of the latest figures available from the Bank of England.
Accountancy firm Moore Stephens reports that six of the top ten areas that took out the highest number of risky mortgages are in South West London.
Wandsworth takes top spot and also in the top ten are Streatham (2nd), Croydon (3rd), Wimbledon (5th), Clapham (6th) and Tooting (7th).
In total, there were 71,273 'risky' mortgages taken out in the UK during 2015.
The Bank of England considers a mortgage to be 'risky' if the borrower is lent 4.5 times their salary or more.
Moore Stephens says that many homeowners have been 'lulled into a false sense of security' by record low interest rates.
The firm warns that future interest rate rises could mean more homeowners not being able to meet their monthly repayments - particularly those on variable-rate or short-term fixed rate products.
“Despite preventative measures being put in place to calm the market, homeowners taking on too much risk with their mortgages is still a real problem," says Jeremy Willmont, head of restructuring and insolvency at Moore Stephens.
He suggests that homeowners may have become 'too comfortable' with the low interest rates that have been in place in recent years.
“Some homeowners are stretched even with interest rates at their current record low, so an increase of just half a percentage point would represent a significant relative jump in mortgage repayments," says Willmont.
“Young professionals are overstretching themselves to buy homes in new London hotspots. Too many ignore the possibility of a decline in house prices or that their salaries will not rise faster than inflation."
He says that the Bank of England may be concerned by these figures, particularly as it introduced measures to control risky lending in 2014.