Boris Johnson met Manchester United vice-chairman Ed Woodward in Number 10 just days before the launch of the European Super League, it's emerged.
It's thought the football chief was in Downing Street to discuss Covid protocols and the return of fans to stadiums.
But it's also believed he was introduced to the Prime Minister after the formal meeting.
Labour have demanded the release of the minutes of the meeting.
Shadow Culture Secretary Jo Stevens said: "The Prime Minister and his ministers made very public and vocal condemnation of the European Super League.
"The public would therefore expect the same message to have been delivered in any private meetings.
"Downing Street should release the minutes in order to clear up any confusion and avoid accusations of hypocrisy."
It's understood Mr Woodward was introduced to the Prime Minister after bumping into him in a corridor, following the meeting with No10 chief of staff Dan Rosenfield on Wednesday last week.
Downing Street insisted the talks did not cover the breakaway European competition. A spokesman said: “The Super League was not discussed and the PM was not in the meeting.”
No10 said the PM first became aware of the Super League "on Sunday, as everybody else did".
The Independent reported Manchester United sources said that Mr Woodward's talks with Mr Rosenfield were "around Covid restrictions and the return of fans to stadiums".
News of the competition involving Manchester United and five other English teams, along with sides from Spain and Italy, broke on Sunday night.
The proposed league swiftly and spectacularly unravelled and Manchester United announced Mr Woodward would leave by the end of the year following a backlash by fans, the football authorities and the Government.
The Government finally published plans last night for its 'fan-led review' of football in the wake of the European Super League row.
Setting out details of the probe, ministers said it would talk to fans across the country to find ways to improve the governance, ownership and sustainability of clubs in English football.
The panel, to be chaired by Tory MP and former Sports Minister Tracey Crouch, will examine whether current tests for club owners and directors are fit for purpose.
It will also look into how money flows through the whole Football "pyramid" - and how club finances are scrutinised.
And it will consider calls for a single, independent football regulator, to oversee regulations and compliance.
The review was originally promised in the Tories' 2019 manifesto, after a number of high-profile collapses of local clubs, including Bury FC.
In response, the review will look at how government might intervene to protect club identity, including geographical location and historical features like club badges.
