A former contractor for the US Internal Revenue Service (IRS) who pleaded guilty to leaking tax information to news outlets about former president Donald Trump and thousands of the country’s wealthiest people was sentenced to five years in prison on Monday.

Charles Edward Littlejohn, 38, of Washington, DC, had pleaded guilty to one count of unauthorised disclosure of tax returns and return information. He gave tax information to two news outlets, The New York Times and ProPublica, between 2018 and 2020.

US District Judge Ana Reyes said she handed down the highest possible sentence to deter anyone else who might feel “an obligation to break the law”.

Littlejohn apologised to the people affected and said he expected to face consequences. “I acted out of a sincere, if misguided, belief I was serving the public interest,” he said. Instead, “my actions undermined the fragile trust we place in government”.

Defence lawyer Lisa Manning argued for a lower sentence in line with typical guidelines for someone without a criminal record. The judge, though, said the crime was extraordinary because Littlejohn targeted the president.

“When you target the sitting president of the United States, you target the office,” she said. “It can not be open season on our elected officials.”

She also sentenced Littlejohn to three years of supervised release and a 5,000-dollar (£3,940) fine.

Republican Senator Rick Scott of Florida said he was among those whose tax information was leaked by Littlejohn.

He said the possibility it could be published affects his entire family and Littlejohn should have faced additional criminal charges from the Justice Department for exposing personal information “just to harm people”, he said.

Justice Department prosecutors did not name the outlets in the charges, but the description and time frame align with stories about Mr Trump’s tax returns in The New York Times and reporting about wealthy Americans’ taxes in the nonprofit investigative journalism organisation ProPublica.

The 2020 New York Times report found Mr Trump, who had broken with tradition and refused to voluntarily release his tax returns, paid 750 dollars (£591) in federal income tax the year he entered the White House and no income tax at all in some years thanks to colossal losses.

Six years of his returns were later released by the then-Democratically controlled House Ways and Means Committee.

ProPublica, meanwhile, reported in 2021 on a trove of tax-return data about the wealthiest Americans. It found the 25 richest people legally pay a smaller share of their income in taxes than many ordinary workers do.

Both publications have declined to comment on the charges, and ProPublica reporters previously said they did not know the identity of the source.

The stories sparked calls for reform on taxes for the wealthy — and calls for investigations into the leaking of tax information, which has specific legal protections.

The IRS has said any disclosure of taxpayer information is unacceptable and the agency has since tightened security.