Plastic bags were posted through letterboxes in Balerno last week, instructing householders to give any unwanted clothes to the organisers, Supporting Arms.
But alarm bells rang on closer examination when it emerged the bags did not cite any registered charity numbers, yet did describe worthwhile communities in need of goods overseas.
Resident Phil Carson, 43, an engineer, said: "The wording on the bag is very strange indeed and seems to imply the money goes to charity. It says there are lots of needy people in Eastern Europe and in Africa."
Mr Carson is one resident to have alerted Trading Standards to his concerns, prompting an investigation by staff.
It is understood Supporting Arms – a registered company but not a charity – has come to the attention of authorities across the UK previously, owing to similar concerns by the public.
Charity experts said it was legal to collect unwanted donations from households in such a manner, allowing companies to then sell on the goods, possibly in the countries mentioned on the collection sacks.
Edinburgh Pentlands MSP David McLetchie, who was contacted by his constituent Mr Carson after he received one of the collection bags, said it was "sickening" if residents were being led to believe they were donating to charity.
A spokesman for the Institute of Fundraising, which has an office on Calton Road, urged the public to be aware that not all door-to-door collections were the same.
He said: "We do understand that some people do just want to recycle their goods through donation, but we encourage the public to be aware that not all collections are for charitable purposes." He said the Institute would now be working hard to promote public awareness of the issue, having recently held discussions with the Scottish Government, and stressed anyone wishing to donate to charity should scrutinise any collection bag posted to their property.
A Trading Standards spokesman said: "We have been made aware of this and it is something we are currently investigating. If anybody feels they have been misled then we would urge them to get in touch with information."
There was no one available for comment from Supporting Arms.