The chief executive of California’s embattled high-speed rail authority abruptly resigned on Wednesday, over a month after a state watchdog determined the agency had misused public funds.

In September, California’s office of the inspector general released an investigative report finding that the rail authority had paid $543,000 in travel-related reimbursements for consultants that were not allowed, including international or out-of-state travel expenses.

The report raised questions about whether business and pleasure was mixed under chief executive Ian Choudri’s purview. The rail authority paid $81,000 for consultants’ travel expenses to places that lacked an official purpose, including gyms, an escape room and a nightclub.

In his resignation email, which CalMatters obtained, Choudri cited “important personal and family priorities”.

“This has not been an easy decision, as leading the authority has been one of the most meaningful and rewarding chapters of my professional life,” he wrote.

Choudri was sworn into the rail authority’s top post in 2024.

The agency is tasked with constructing a high-speed rail line that would slash the commute time between Los Angeles and San Francisco, which are about 380 miles apart.

The bullet train, which initially drew starry-eyed comparisons to the speedy modes of transport in China and Japan, has become a political and financial headache for California.

Eighteen years after the state’s voters gave the green light to a multi-billion bond project, no railroad tracks have been laid, as the agency continues to search for funding.

Its price tag has soared upwards of $100bn. The Trump administration, which has an adversarial relationship with several of California’s top officials, dealt a further blow to the project by withdrawing $4bn last year. At the time, the US transportation secretary Sean Duffy called it a “boondoggle” and a “train to nowhere”.

Xavier Becerra, who is highly favored to be California’s next governor, suggested this week there would be a staff shake-up at the rail authority if he wins the election from his rival Steve Hilton.

“We’re going to have to scrub a lot. The high-speed rail authority’s going to have to look really different if we’re going to continue this project,” Becerra told KCRA News, in an interview that aired hours before Choudri’s exit.

“I need to gain the confidence of the public. I can’t gain it if I keep the same characters in place.”

Joe Stephenshaw, director of California’s department of finance, will serve as interim CEO of the rail authority.