Researchers discovered that each woman has 16 different bras in her underwear drawer, topping up her collection with four new ones every year.

However, each item of lingerie sees an average of seven outings over an eight week period before it gets a wash.

Experts warned that by not washing their underwear frequently, women risk skin irritation through a build-up of bacteria.

While white is the most popular choice of bra colour, the findings also suggest that the contents of women's smalls drawers are suffering aesthetically from the lack of washing.