In response to requests from members of Congress and to at least one news report, the Federal Bureau of Investigation in New York opened a preliminary inquiry on Thursday into allegations that News Corporation journalists sought to gain access to the phone records of victims of the Sept. 11 attacks, according to several people briefed on the matter.

The investigation is in its earliest stages, two of the people said, and its scope is not yet clear. It also is unclear whether the F.B.I. has identified possible targets of the investigation or possible specific criminal violations.

The bureau is “taking a hard look at it from a couple of angles,” one of the people said. The person said the matter was being treated as an assessment, a term the bureau uses to characterize the early stages of an investigation that precede the possible issuance of subpoenas or the use of other investigative tools like wiretaps.

The inquiry was prompted in part by a letter from Representative Peter T. King, a Long Island Republican, to Robert S. Mueller III, the F.B.I. director, in which he asked that the bureau immediately open an investigation of News Corporation, citing news reports that journalists working for its subsidiary, The News of the World, had tried to obtain the phone records of 9/11 victims through bribery and unauthorized wiretapping, the people said.