HS2 has been forced to repay more than £500m to HMRC after an investigation found it had been wrongly reclaiming VAT.
The tax authority ruled that HS2 Limited should not have reclaimed £569.1m incurred on design and construction between 2014 and 2019.
Lord Berkeley, deputy chairman of the review into the high-speed rail project, said: “It is extraordinary that a company of this size that is government-owned should be having questions raised about VAT.”