The Associated Press news agency says the U.S. government has seized two months of telephone records for many of its reporters and editors.
The organization's chief executive, Gary Pruitt, called the action a "massive and unprecedented intrusion" into AP's newsgathering operations.
Pruitt said Monday that the AP learned from the Justice Department on Friday that the government agency gathered phone records for more than 20 separate phone lines of AP offices and journalists.
He said the records cover a two-month period in early 2012 and include AP bureaus in New York, Washington and Hartford, Connecticut.
An Associated Press story on the matter says the government has not given any explanation why the phone records were seized.
However, the story notes that U.S. officials have previously said the Justice Department is conducting a criminal investigation into who may have provided information for an AP story in May, 2012, about a CIA operation in Yemen that foiled an al-Qaida bomb plot.
The U.S. Attorney's Office in Washington said in a statement Monday that it is "always careful and deliberative" when dealing with issues of the press. It did not specifically mention the Associated Press case.