HM Revenues and Customs says it plans to used “web robot” software to crawl the Internet for evidence of individuals and companies evading tax.

The proposed system will integrate data collected from websites with HMRC’s Connect system, which compares tax records with third party information sources to discover incidents of tax evasion.

The technology will support four forthcoming campaigns by HMRC. These will target ‘VAT rulebreakers’, individuals offering paid training without paying tax, untaxed online marketplaces and traders.

"We will use the information we gather to pursue people who choose not to use the opportunities we provide for them to put their affairs in order on the best possible terms," said HMRC director of risk and intelligence, Mike Wells. “It will be more expensive if we come and find people, so I urge them to come forward and disclose voluntarily.”

Connect is based on a system called NetReveal from BAE Systems’ IT security subsidiary Detica. According to a departmental report in 2009, the system uncovered VAT repayment fraud worth £330 million in its first year of use.