Pakistan’s National Accountability Bureau (NAB) arrested Mir Shakilur Rehman, the editor-in-chief of the Jang Media Group, on Thursday.

The Jang Media Group is one of the largest independent media companies in Pakistan. It owns Urdu-language Geo News, the largest news channel in Pakistan, along with several major newspapers.

NAB arrested Rehman for an alleged illegal purchase of 54 kanals of land dating back to 1984. Rehman’s team has indicated that this land purchase was legal.

In a statement, NAB presented evidence that raises questions about the legality of Rehman’s ownership of the property, but there continue to be ongoing disputes about the legitimacy of this evidence. When the Lahore Development Authority received two complaints from individuals who claimed they owned some of the land in question, it dismissed both complaints. Lower courts in Lahore have also dismissed related lawsuits.

Rehman’s arrest has been widely condemned as an attack on the freedom of the press. Media advocacy groups, like the Committee to Protect Journalists, have called for his immediate release.