Microsoft has removed Gold partner status from India-based support firm Comantra amid claims that the firm had been defrauding Redmond's UK customers.

The firm is alleged to have masqueraded as Microsoft when cold-calling customers and to have told these customers that it had found fictitious viruses on their PC systems which it could "remove" for them – in some instances at a cost of £185, PC Pro reports.

In a statement sent to The Reg, Microsoft said: "Following an investigation, the allegations were confirmed and we took action to terminate our relationship with the partner in question and revoke their Gold status."

"There are no circumstances under which we would ever allow partners or any other organisations to pose as Microsoft. We view matters such as these extremely seriously and take immediate action if such behaviour is brought to our attention and found to be the case," a spokesman added.

However, as noted by the report, complaints about Comantra cold-calling scams are not new, in fact they date back to 2009 – and Microsoft's own public forum had posts from worried users.

Comantra has been slow to pull the Gold Partner logo from its site in the week since it was notified by Microsoft of the results of the investigation, but insists that it is in the process of doing so.

The Reg cold-called director Rajesh Bajaj, who denied his firm had scammed individuals or businesses into believing they had viruses on their PCs. Bajaj said he suspected his company had been the victim of unscrupulous rivals in India and the UK.

He said Comantra was striving to improve the quality of service and had applied for ISO certification.

A Microsoft survey of 7,000 users earlier this summer found that on average 16 per cent of respondents had received calls at home from someone purporting to be a Microsofter offering free security checks.

Microsoft advised customers to seek guidance on steering clear of scammers to visit its Safety and Security Center. ®