Dozens of people working for HS2 Ltd are being paid at least £150,000 a year.
PA news agency analysis of Cabinet Office figures shows the earnings of 44 people at the taxpayer-funded company were at that level at the end of September last year.
Their combined pay was up to £8.8 million.
Outgoing chief executive Mark Thurston was the highest earner.
This was up from £618,144 during the previous 12 months, representing a rise of more than 9%.
His job is described as delivering the high-speed railway “to safety, cost, time and quality standards”.
It was announced in July that Mr Thurston will step down by the end of this week after six-and-a-half years in the role.
Chief commercial officer Ruth Todd received a total package worth £313,055.
Conservative MP for Buckingham Greg Smith, who has long been a strong critic of the project, said: “The absolute cheek of HS2 bosses suckling on the taxpayer teat to such great excess whilst presiding over massive cost-ballooning of the project.
“It defies belief.”
An HS2 Ltd spokesman said: “HS2 is Europe’s biggest infrastructure project and it is necessary to employ people with the right level of expertise to deliver it successfully.
“HS2 Ltd is committed to controlling costs and takes its responsibility towards value for money very seriously.
“Remuneration is also benchmarked against comparable organisations and managed in line with the Government’s public sector pay policy.”
HS2 Ltd’s annual report shows expenditure on consultants was £25.8 million in 2022/23.
That is down from £32.1 million during the previous 12 months.
HS2 Ltd also made four statutory redundancy payments totalling £19,414 in the financial year.
Reports have suggested that Prime Minister Rishi Sunak has been warned the price tag for HS2 may have soared past £100 billion, even though the Government has already scrapped the Leeds leg.
The first estimate in 2010 of the proposed high-speed rail link between London and the North was £30 billion.
In response to soaring costs, there is speculation Mr Sunak is considering cancelling or delaying HS2 between Birmingham and Manchester, as well as permanently stopping the line at Old Oak Common, west London, rather than London Euston.