Britain has launched a criminal inquiry into the workings of Indian giant Tata Steel, which is seeking to sell its loss-making UK businesses, according to a media report on Friday. According to 'The Daily Telegraph', police officers are examining allegations that staff working for the company's office in Britain may have falsified certificates detailing the composition of its product before sale. Tata Steel is believed to have referred itself to the Serious Fraud Office (SFO) after an internal inquiry at its Yorkshire site in northern England. The SFO said that it was "declining to comment" on the matter at this stage. Tata Steel has also not commented on what they have termed as "media speculation" so far. The newspaper quoted "well-placed sources" saying that the documents being examined affected 500 customers, including global giants like BAE and Rolls-Royce. A Rolls-Royce spokesperson said: "We were made aware of an issue by Tata last year. We have not been contacted by the SFO and cannot comment on any investigation". The SFO inquiry is understood to centre around certificates that are produced to verify the composition of steel. Auditors found material that suggested inappropriate testing and certification may have occurred. At least nine employees of the firm have been suspended. There is no suggestion that the information on the certificates has led to any safety concerns, the newspaper reports. A trading standards investigation in also ongoing, but it is unknown whether they are linked. The news comes against the backdrop of a major crisis in the UK steel industry after Tata Steel announced its plans to sell off its loss-making units in the country. UK business secretary Sajid Javid flew down to Mumbai earlier this week to hold talks with Tata chairman Cyrus Mistry in an attempt to find a solution that would help save the nearly 15,000 jobs on the line. It is believed a deal to save Tata's Scunthorpe plant can be reached as early as Monday with UK-based investment firm Greybull Capital. Meanwhile, Indian-origin tycoon Sanjeev Gupta has stressed that his Liberty Group has the resources to rescue the firm's other units. He will be in Scotland on Friday for the official handover of two Lanarkshire plants previously owned by Tata Steel, which his firm had acquired last year.