The International Press Institute (IPI) today said that it was deeply troubled by news that the U.S. Justice Department secretly seized two months of telephone records of Associated Press (AP) journalists and the group demanded an explanation.

AP CEO Gary Pruitt protested the “massive and unprecedented intrusion” into AP’s newsgathering activities in a letter to Attorney General Eric Holder posted online yesterday.

The AP learned Friday that federal prosecutors earlier this year subpoenaed records for April and May 2012 for office, home and mobile telephone lines associated with more than 20 AP journalists. Reports indicated that the seizure may have been connected to an investigation into the source of information behind a May 7, 2012 AP report on a foiled terrorist plot.

The Justice Department reportedly declined to confirm the reports. In a vague statement released today to Business Insider, the Department said that “we value the freedom of the press” and implied that notifying AP in advance of the subpoenas would have posed “a substantial threat to the integrity of the investigation.”

Pruitt, however, noted in his letter: “There can be no possible justification for such an overbroad collection of the telephone communications of The Associated Press and its reporters. These records potentially reveal communications with confidential sources across all of the newsgathering activities undertaken by the AP during a two-month period, provide a road map to AP’s newsgathering operations, and disclose information about AP’s activities and operations that the government has no conceivable right to know.”

John Yearwood, world editor for The Miami Herald and chair of IPI’s North American Committee, said the case “appears to be a clear case of overreach by the Justice Department”. He commented: “It’s the sort of thing you would expect to see in authoritarian regimes. We call on the government to justify its need for such a broad collection of phone records.”

IPI Executive Director Alison Bethel McKenzie added: “We agree with AP that this action constitutes ‘a serious interference with AP’s constitutional rights to gather and report the news, and we are deeply troubled by the disrespect for the rights of journalists and media outlets under the First Amendment that it appears to show. This incident serves as a chilling reminder of the fundamental need for Congress to adopt a journalist shield law.”

Forty-nine states and the District of Columbia provide a qualified privilege for journalists in various proceedings, but there is no such protection at the federal level. The House of Representatives approved a bill to create a shield law in 2007 and in 2009, but both measures ultimately died in the Senate.

IPI today also endorsed Pruitt’s demands that the Justice Department return the records that it seized and destroy all copies or, at a minimum, segregate them and prohibit any reference to them until the matter can be sorted out. IPI further echoed Pruitt’s call for “an immediate explanation as to why this extraordinary action was taken, and a description of the steps the Department will take to mitigate its impact on AP and its reporters”.