CIA investigates allegations of Senate staff monitoring
The Central Intelligence Agency is investigating allegations it improperly monitored members of the US Senate intelligence committee.
A CIA internal watchdog has been tasked with determining if the agency accessed the computers of Senate staff.
The Senate committee was tasked with investigating potential past CIA abuse at the time of the alleged breach.
The chairman of the Senate Armed Services committee called the reports, if true, an "extremely serious matter".
Senate intelligence committee chairwoman Dianne Feinstein told US media that CIA inspector general David Buckley was looking into officer actions.
The alleged improper monitoring is said to have taken place as the committee investigated allegations of CIA abuse stemming from a detention and interrogation programme in use under former US President George W Bush.
Ms Feinstein has told US media in the past that the committee's 6,000 page "comprehensive review", completed in 2013, found the CIA programme yielded little or no significant intelligence.
The New York Times initially reported the allegations of CIA monitoring of Senate computer networks, citing an anonymous official.
"Such activity, if it occurred as alleged, would impede Congress' ability to carry out its constitutional oversight responsibilities and could violate federal law," chairman of the Senate Armed Services Committee Carl Levin wrote in a statement on Wednesday.
CIA director John Brennan reacted swiftly to the Senate allegations on Wednesday.
"I am deeply dismayed that some members of the Senate have decided to make spurious allegations about CIA actions that are wholly unsupported by the facts," he said. "I am very confident that the appropriate authorities reviewing this matter will determine where wrongdoing, if any, occurred in either the Executive Branch or Legislative Branch."