Rishi Sunak’s old phone number and a voicemail recording appear to have been leaked online by pranksters in a security breach, according to reports. The incident, first reported by the Sun, involved a longstanding phone number for Sunak that the government had told the Covid inquiry was no longer operational. However, the prank call is believed to have heard the phone ringing and a voicemail recording for Sunak. Asked about the report, No 10 said it never commented on security matters. Boris Johnson was forced to change his phone number when he was prime minister after a similar security breach by pranksters. If the recording highlighted by the Sun is proved to be recent and verified, it may prompt questions for Sunak about why the government has said old messages are no longer recoverable for the Covid inquiry. Sunak told the inquiry he was unable to hand over some WhatsApp messages because he had changed phone several times. In his witness statement to the public inquiry, the prime minister claimed he did not have access to messages from the period when he was running the Treasury because he had failed to back them up. The inquiry, which is hearing evidence in its second stage of examining the government’s handling of the pandemic, had requested key communications sent during the pandemic, from the end of January 2020 to the end of February 2022. The inquiry’s chair, Heather Hallett, had asked the government to provide messages from Sunak, Johnson and nearly 40 other senior figures and advisers. Sunak is reported to have been given a new number on becoming PM. In his witness statement, Sunak, who is expected be the final witness in the second stage of the inquiry, said: “Having changed my phone a number of times over the last three years, I do not have access to the WhatsApp messages that I sent or received during the relevant time, and neither were the messages backed up. “My expectation would be that if the officials on those groups had considered that any information being communicated by WhatsApp message needed to be preserved to form part of the official HMT record, then those officials would have taken steps to ensure that happened.” Simon Case, the cabinet secretary, is among those due to give evidence to the inquiry in the coming weeks after WhatsApp messages showed him writing informally about the government looking like a “terrible, tragic joke” in its response to the pandemic. He is now due to take a short period of medical absence, with the Cabinet Office saying he would be absent “because of a private medical matter and is due to return to work in a few weeks”.