Washington DC - A former Internal Revenue Service (IRS) contractor who leaked former US president Donald Trump's tax returns to the media was sentenced to five years in prison on Monday.

Charles Littlejohn (38) pled guilty in October to unlawfully disclosing tax information.

US District Judge Ana Reyes imposed the maximum penalty of five years in prison at the ex-IRS contractor's sentencing in Washington on Monday.

Littlejohn was accused by federal prosecutors of leaking the tax returns of a "high-ranking government official" to a news organization.

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Neither the official nor the news outlet were identified by the Justice Department but it has been widely reported in US media that the tax returns were those of Trump and the news organization was The New York Times.

The Times reported in September 2020 that Trump, who has refused to make his tax returns public, paid only $750 in federal income tax in 2016 and 2017, and none at all for 10 of the previous 15 years.

Littlejohn was also accused of leaking the tax information of thousands of the wealthiest individuals in the United States to another unidentified news outlet.

That outlet is believed to be ProPublica, a nonprofit journalism organization that published extensive reports in June 2021 based on the tax information, a project it dubbed The Secret IRS Files.

"Charles Littlejohn abused his position as a consultant at the Internal Revenue Service by disclosing thousands of Americans' federal tax returns and other private financial information to news organizations," Acting Assistant Attorney General Nicole M. Argentieri said in a statement.

"He violated his responsibility to safeguard the sensitive information that was entrusted to his care, and now he is a convicted felon," Argentieri added.

According to court filings, Littlejohn accessed tax returns on an IRS database and saved them on multiple personal storage devices, including an iPod.