Antivirus company Avast has suspended its outsourced tech support after allegations that the Indian company carrying out the work has been trying to trick users into paying for unnecessary help.The crunch point seems to have been a blog this week in which influential security writer Brian Krebs investigated Avast's outsourced support company iYogi, finding that its engineers tried to sell him a pricey support service after claiming to find problems with his PC.In fact, Krebs had installed Windows XP on his Apple using a virtual machine utility just before calling the company helpline and the various faults the engineer claimed to have detected using a remote support tool were non-existent.After being quoted $169.99 (APS108) for general support, Krebs was told that his Avast antivirus installation was not working correctly either and he should upgrade from the free to the paid version of the software."I've frequently recommended AVAST! antivirus software to those seeking a free alternative," said Krebs. "But I can't understand why a company like this would risk its reputation by partnering with a support organization whose sales tactics are practically indistinguishable from those employed by peddlers of fake antivirus software or "scareware."The revelation has prompted Avast - which last December announced a $200 million US IPO - to suspend its contract pending an investigation."We had initial reports of this behavior a few weeks ago and met with iYogi's senior executives to ensure the behavior was being corrected," said an official Avast statement."Thus, we were shocked to find out about Mr Krebs' experience. As a consequence, we have removed the iYogi support service from our website and shortly it will be removed from our products.  Over the next weeks, we will work with iYogi to determine whether the service can be re-launched.""In the meantime, users can receive support via the other support options provided on our website. We will also work to ensure that any users that feel they have been misled into purchasing a premium support receive a full refund," it read.A previous statement made by Avast on 14 March admitted it had received complaints about fraudulent cold call support without naming the entity responsible.Avast's 'freemium' business model has seen the free version of its antivirus client become according to recent OPSWAT global figures the world's most popular single antivirus program; Microsoft's Security Essentials (MSE), also free, is at number two globally and number one in the US market.As with others adopting the same model, Avast depends on converting a percentage of free users to paid version of the product offering more features.