The digital secretary has told MPs a criminal investigation into how the secret discussions of the National Security Council were leaked has not been ruled out.
The government is facing demands for an official inquiry over reports that the involvement of Chinese tech giant Huawei in the UK's new 5G network was approved at this week's NSC in the face of opposition from some ministers.
Prime Minister Theresa May signalled her anger at the unprecedented breach, which normally surrounds a forum where the most senior government ministers are briefed by heads of security and intelligence agencies MI5, MI6 and GCHQ.
Mrs May's official spokesman declined to say whether a leak inquiry had been launched, but told reporters: "The prime minister is clear that the protection of information on matters of national security is of the highest importance."
Digital, Culture and Media Secretary Jeremy Wright told the House of Commons: "We cannot exclude the possibility of a criminal investigation."
He suggested investigators from the Security Service, MI5, could be brought in "to make the culprit feel very uncomfortable".
In an urgent question to the House of Commons, shadow Cabinet Office minister Jo Platt said: "If a minister did leak the information, they are not fit to serve in the Cabinet - and are certainly not fit to be prime minister.
"Critical issues of national security should be handled with utmost care, not used as political ammunition in a Tory party civil war.
"A full leak inquiry should be undertaken and, if identified, the individual should immediately resign or be removed from their position."
Mr Wright repeated the government's position that no final decision has been made on whether Huawei should be allowed to bid for contracts in the hi-tech communications project.
Words by Wesley Hudson