Home Secretary Suella Braverman was probed by national security officials earlier this year as part of a leak inquiry, it has been reported.
The claim raises further questions about the decision by Rishi Sunak to reappoint Ms Braverman as Home Secretary just six days after she resigned from the job for mishandling sensitive information.
A report in the Daily Mail newspaper claims the rule-breaking minister was previously probed in January as part of a security breach relating to a British spy.