A top consultant for California’s controversial high-speed rail project is under investigation after he modified a multi-million dollar contract that involved a company in which he may have held more than $100,000 in stock.

At the request of California state Assemblyman Jim Patterson, a Republican and major critic of the bullet train project, the Fair Political Practices Commission launched an investigation last week into the deputy chief operating officer for the California High-Speed Rail Authority, Roy Hill.

Hill, who is also a senior executive at the lead consulting firm WSP, signed a $51-million change order for the construction team led by the Spanish firm Dragados. Hill, however, may have also owned more than $100,000 stock in Jacobs Engineering, which is part of the Dragados team, according to the Los Angeles Times.

WSP suspended Hill on Monday at the direction of the rail authority. Hill will remain suspended until the investigation is resolved.

CALIFORNIA BULLET TRAIN PROJECT ON TRACK TO BLOW THROUGH BILLIONS OF MORE DOLLARS

“We hold ourselves to the highest ethical standards,” Denise Turner Roth, chief development officer for WSP USA, said in a statement. “We take these allegations seriously, and will cooperate fully with the investigation. Mr. Hill has been temporarily suspended while this matter is reviewed.”

The investigation into Hill marks another setback for the controversial rail project, which California Gov. Gavin Newsom vowed to plow forward with earlier this year – albeit in a reduced capacity.

In his first state of the state address earlier this year, Newsom said he was shelving plans for a high-speed rail line between Los Angeles and the San Francisco Bay Area, and instead moving ahead with a line between Bakersfield and Merced through the state’s agricultural heartland.

The embattled $77 billion bullet train - which had long been championed by Newsom's predecessor, Jerry Brown - is years behind schedule, with the latest estimate for completion set for 2033. Bullet train planners had been under increasing pressure to make progress on the system that many believe had no plausible way of living up to its goal of getting riders across the state in three hours or less.

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President Trump has threatened to pull federal funding for the project and force the state to pay back money already doled out.

So far, the Federal Railroad Administration has given California $2.5 billion to construct a high-speed railway between Los Angeles and San Francisco, with another $929 million pledged. But federal authorities – and the president – claim the terms of the grant have not been met and have threatened to withhold any future payments while demanding repayment for the funds already doled out to California.