The campaign urges people to make sure they "Give With Care"

The Association of Charity Shops says up to �3m a year is lost through theft and collections by companies which people wrongly believe are charities.

The two bodies have joined forces with the government to launch a consumer advice campaign.

The majority of clothing collections are organised by legitimate charities.

Misleading

Commercial companies which collect clothing from households to sell for profit are not necessarily breaking the law, unless they wrongly claim to be acting as or for a charity.

Charities are losing substantial sums of money to anonymous 'bogus' collectors Phil Hope, Govenrment minister

However campaigners fear consumers could be misled into donating goods in the mistaken belief that they are helping charity.

According to the Association of Charity Shops, UK charities raise �68m a year selling donated clothes on the high street, much of it gathered from doorstep collections.

But it estimates that the sector loses between �2.5m and �3m a year through a combination of donations lost to commercial companies and theft.

"Charities are losing substantial sums of money to anonymous 'bogus' collectors that mislead donors into thinking they are charities," said government minister Phil Hope.

"While the law can deal with those that falsely claim to be either charities or collecting on behalf of charities, it is extremely difficult to trace these anonymous collectors."

Top tips

WHAT TO LOOK OUT FOR Check that a specific charity is named. Watch out for vague wording like "helping sick kids". Look for a registered charity number, not just a registered company number. Make sure the organisation has provided contact details. Legitimate charities will do this. If in doubt, go online to www.charitycommission.gov.uk or call 0845 3000 218. Source: The Charity Commission

Dame Suzi Leather, chair of the Charity Commission, stressed that most of the leaflets which come through the door are from genuine registered charities.

She urged consumers not to stop supporting such initiatives, but to make sure they were clear who would benefit from any donation.

Legitimate collection sacks will include the charity's name, registered number and contact details.

"Christmas is a really important fundraising time of the year for many charities, and they need every penny from your donations they can get," she said.

"If you want to make sure your unwanted clothes are going to help a genuine charity, use our top tips."

Consumer leaflets are being distributed throughout the country in areas where problems have been reported, including the West Midlands, north east London, Bristol and Gloucester.

Organisations which run genuine charity clothing collections have also reported an increase in the theft of donated goods.

Clothes Aid collects second hand garments to raise money for a range of charities, mainly hospitals.