A man in the US has been charged with leaking the tax returns of a "high-ranking government official" who is understood to be Donald Trump.
Prosecutors said Charles Littlejohn, a contractor for the IRS - the US-wide tax body - stole the information and passed it on to a news organisation.
He is also accused of stealing tax return information of "thousands" of the US's "wealthiest individuals".
The Department of Justice alleges this data was given to another outlet.
Court documents say the two news organisations published "numerous articles" based on this information.
Neither have been charged with any wrongdoing.
Although the court documents do not name the government official, a source has confirmed to the BBC's partner in the US, CBS News, that it is former president Donald Trump.
The same person also said that the news organisation which received information about Mr Trump's tax returns was The New York Times, while the second, which received information about other individuals was the ProPublica website.
The New York Times declined to comment to CBS News about the claims, while ProPublica said in a statement to the outlet: "We have no comment on today's announcement from the DoJ. As we've said previously, ProPublica doesn't know the identity of the source who provided this trove of information on the taxes paid by the wealthiest Americans."
There has been no public comment from Mr Trump.
Court documents claim that between 2017 and 2021, Mr Littlejohn worked for an unnamed consultancy which in turn worked on contracts from the US Department of the Treasury's IRS, dealing with tax administration.
The papers go on to allege that between 2018 and 2020, while Mr Littlejohn was working on an IRS contract "he stole tax returns and return information", some of which dated back more than 15 years.
The charge against Mr Littlejohn is the unauthorised disclosure of tax returns and return information. If convicted, he faces up to five years in prison. There has been no public comment from the Washington DC resident.
A 2020 article in The New York Times, which is thought to have been based on the leaked information, claimed that Mr Trump paid just $750 (£580) in federal income tax both in 2016, the year he ran for the US presidency, and in his first year in the White House.
The newspaper also said that he paid no income taxes at all in 10 of the previous 15 years and that the records reveal "chronic losses and years of tax avoidance".
