A common citrus agent used in many perfumed products reacts with air to produce a well-known carcinogen

A scent found in perfumed candles is believed to produce a cancer-causing substance, new research has found.

Researchers from the BBC along with Professor Alastair Lewis from the University of York analysed the air quality inside a series of similar houses for a range of "volatile organic chemicals".

The chemical found most prevalent in the houses was limoncene. It is commonly used to give scented candles, air fresheners and body sprays a citrus smell

When released into the air, Limoncene reacts with ozone to produce formaldehyde, a carcinogenic substance.

Formalydehyde has been linked to cancer since the 1980s and has been listed as a known human carcinogen since 2011.

It is found in some furniture and is created by burning cigarettes and gas stoves.

The researchers discovered the best way to reduce levels of formaldyde in the air was to place houseplants around the house which then absorbs the carcinogen.

According to scientists - geraniums, lavender and a series of ferns are the best at absorbing formaldehyde.