Retail giant Wal-Mart said on Monday it had sacked a systems technician for recording telephone conversations involving a New York Times reporter without authorisation.
Wal-Mart said it informed federal prosecutors about the recording and also told the New York Times. It said the actions did not appear to violate any laws but were a contravention of company policy.
"These recordings were not authorized by the company and were in direct violation of the established operational policy that forbids such activity without prior written approval from the legal department," Wal-Mart said in a statement.
"No such approval was ever sought and, had such approval been sought, it would have been denied."
Wal-Mart said its internal investigation found that the systems technician had recorded telephone conversations between Wal-Mart public relations associates and a reporter from The New York Times between September 2006 and January 2007.
"Under federal law and the applicable state law, a telephone conversation may be recorded if one party has given his or her consent," the company said.
"Since Wal-Mart policies state that all electronic communications of associates using Wal-Mart communication systems are subject to monitoring and recording, Wal-Mart associates give their consent to the monitoring and recording of their calls.
"Therefore, the unauthorized recording of telephone conversations by the systems technician did not violate any laws."
Nonetheless, the company said that on March 1, federal prosecutors notified Wal-Mart that a federal investigation would be opened on the matter.
The news comes several months after a scandal at computer giant Hewlett-Packard in which private detectives were hired to find the source of leaks within the company, and involved spying on board members and journalists.
Wal-Mart said it began its internal investigation on January 11 after a tip from an employee under 'the Wal-Mart open door policy'.
Wal-Mart said that the employee, who was not named, also intercepted text messages involving non-employees, in violation of company policy.
Wal-Mart did not name the reporter for The Times. But the daily said its reporter who has covered Wal-Mart extensively is Michael Barbaro.
A spokeswoman for The Times issued a statement saying: "We are troubled by what appears to be inappropriate taping of our reporter's conversations. At this point, we don't know many of the key facts, such as what the purpose of this taping was and the extent, if any, to which the action was authorised."