BOSTON — Sensitive financial and health data belonging to millions of veterans and stored on a benefits website is at risk of being stolen or otherwise compromised, according to a federal employee tasked with cybersecurity who was recently fired as part of massive government-wide cuts.

The warning comes from Jonathan Kamens, who led cybersecurity efforts for VA.gov — an online portal for Department of Veterans Affairs benefits and services used by veterans, their caregivers and families. Kamens was fired Feb. 14 and said he doesn’t believe his role will be filled, leaving the site particularly vulnerable.

“Given how the government has been functioning for the last month, I don’t think the people at VA … are going to be able to replace me,” Kamens told The Associated Press Monday evening. “I think they’re going to be lacking essential oversight over cybersecurity processes for VA.gov.”

Kamens said he was hired over a year ago by the U.S. Digital Service, whose employees’ duties have been integrated into presidential adviser Elon Musk’s Department of Government Efficiency, which is leading the downsizing effort. Kamens was a digital services expert and the VA site’s information security lead when he was fired by email at night, along with about 40 other USDS employees, he said.

Millions of people use the VA.gov website monthly, Kamens said, and the department is responsible for securing private health and financial information including bank account numbers and credit card numbers. Others on the team will focus on protecting the site, but his expertise can’t be replaced, he said, noting he was the only government employee with an engineering technical background working on cybersecurity.

“VA.gov has access to a huge number of databases within VA in order to provide all of those benefits and services to veterans,” Kamens said. “So if that information can’t be kept secure, then all of that information is at risk and could be compromised by a bad actor.”

Peter Kasperowicz, a Veterans Affairs spokesman, said the loss of a single employee wouldn’t affect operations, and noted that hundreds of cybersecurity workers are among the department’s staff of nearly 470,000.