Sir Nick Clegg is believed to be part of a leak investigation being launched by the British government after sensitive material about changes to social media rules was released.
The former Liberal Democrat leader, who was deputy prime minister in David Cameron's Coalition Government, is understood to have cited secret information in a Zoom call with government officials in June 2020.
But a recent article in the Financial Times, which revealed confidential material from a senior technical executive, has now prompted an investigation into the potential leaking of information by government officials.
The government is presently working on an Online Safety Bill which aims to limit harmful content on social media platforms.
It fears potential reforms, which had been released to a handful of people, have been leaked.
The allegations against Sir Nick, who was recently promoted as head of global affairs at Meta, which runs Facebook, have been denied by the company.
Meta says the claims he has received confidential information are "absurd and false". The company told The Times it was "not aware" of an investigation.
"Any insinuation or suggestion that due to Nick Clegg's previous role in Government he is now seeking or soliciting documents from officials is absurd and false," a Meta representative said.
"We are not aware of any inquiry into this issue by the Government and that is a matter for them.
"As for the alleged content of a Zoom call involving Nick Clegg in June 2020, we have no idea what this is specifically referring to and would need more substantiated detail to respond in full."
The Cabinet Office said it could not confirm or deny whether Sir Nick was the subject of a leak inquiry.