Former judge Sir Andrew Park has been lined up to investigate deals by tax authorities to waive millions of pounds off unpaid company bills.
He will look into 10 deals by HM Revenue and Customs (HMRC) for the National Audit Office (NAO), according to Channel 4 News.
They include the decision by HMRC to wipe £10 million of interest on a £30 million Goldman Sachs bill from a failed tax avoidance scheme on bankers' bonuses.
Dave Hartnett, the country's top tax official, who will retire next summer, is said to have personally sealed the agreement last November, after being advised by an official that there was a "legal impediment" to charging interest.
Sir Andrew, a retired High Court judge, has presided over major tax cases during his career, including hearings on the impact of Europe on the UK tax system.
A spokesman for the NAO said: "No appointment has been made yet and we are still working on the remit of the inquiry."