A senior HS2 executive has resigned after the public spending watchdog found evidence of unauthorised redundancy payments worth nearly £2million.

Steve Allen announced that he would be stepping down from his role as chief financial officer after the National Audit Office found that the £56 billion rail project, which has been dogged by a myriad of delays and controversies, had ignored orders from the Department for Transport that its redundancy scheme should be restricted to statutory levels.

A report by the NAO revealed that the company been operating a redundancy scheme “at enhanced terms without the necessary approvals”.

Mr Allen said that both the HS2 executive and board had been “misinformed about the status of critical approvals for redundancies.”

He added: “Those assurances were given by teams for which I was responsible and, obviously, I regret that.

“So, whilst we are now putting in place the measures to strengthen financial governance systems and to provide robust financial stewardship for the company, I believe it will be appropriate for me to move on.”