Two men have been arrested under the Terrorism Act by officers investigating the breach of data from the Police Service of Northern Ireland (PSNI).
The suspects are aged 21 and 22 and were held following a "search in the Portadown area on Saturday", the PSNI said on X, formerly known as Twitter.
They have since been released on bail to allow for further enquiries, police said.
The force added: "The arrests are part of our investigation into criminality linked to the freedom of information data breach."
Sky's senior Ireland correspondent, David Blevins, said the arrests were "not related to the data breach itself".
He added: "The Northern Ireland Policing Board has ordered an independent review of how the names of 10,000 officers and staff were mistakenly released.
"But detectives are also investigating how the information has been distributed and have made a number of similar arrests in the last three weeks."
The data was leaked when the PSNI published the information in response to a Freedom of Information request.
On Friday, it emerged that PSNI officers were investigating an "attempt to intimidate" officers after a poster claiming to reveal their details was put up near a bus stop.
The force has since confirmed the poster was fake and contained incorrect details.
A woman who said her name was on the poster says she is "outraged" and not a police officer.
In a statement released through a solicitor, she said: "My personal information was written on the poster that was put up in Dungiven that linked myself, my partner and two other named individuals to the PSNI.
"I live in a small rural village and everyone in the area who has seen the poster thinks it is referring to me, although everyone would know that I am not a police officer.
"I can categorically clarify that I am not a serving police officer and I have never been employed by the police in any capacity.
"This is just plain wrong and I am outraged that I have now potentially been made a target for an imminent attack on my life."
She also said she was "deeply upset and concerned" and claimed the PSNI "refused my request to issue a statement confirming that I am not a police officer".
A PSNI spokesperson said they could "confirm that the person raising these concerns has no current or historic links to the police service".
Detective Chief Inspector Avine Kelly said: "We continue to work toward establishing those who possess information relating to last week's data breach, and will take action to ensure that any criminality identified is dealt with robustly to keep communities, and our officers and staff who serve them, safe."