WET washing dried indoors can pose a serious health threat for people with weakened immune systems or severe asthma, doctors have warned.

Research shows clothes draped on drying frames or warm radiators can raise moisture levels in the home by up to 30 per cent, creating ideal breeding conditions for mould spores.

Experts are particularly concerned about Aspergillus fumigatus spores, which can cause lung infections.

Craig Mather, a fast food manager and father of three from Bolton, contracted TB in 1997. The disease left his lungs weak and aggravated the problems he had been left with after childhood asthma.

The 43-year-old said: "I only started to recover when my consultant diagnosed chronic pulmonary aspergillosis and prescribed me special drugs to fight the fungal infection.

"However, I noticed coughing fits and night sweats particularly when I had wet washing drying on the warm bedroom radiator.

"He told me that it could be making my problems worse, so for the last 12 months I haven't dried my clothes indoors and I've notice a huge improvement in my health. I can't do strenuous physical activity, but I am off the drugs and only have to go back to the clinic for check-ups - and I'm able to ride my bike again."