Dubai: Uefa has given Fifa until 2 November to provide key documents and respond to questions concerning its governance and decision-making processes.
At Thursday’s Fifa Council meeting, president Gianni Infantino apologised for his World Cup sell-off plan, but did not fully explain how the proposal had been developed.
In a letter obtained by BBC Sport, Uefa general secretary Theodore Theodoridis said world football’s governing body had left "a number of fundamental questions" unanswered.
"Others remain unanswered, and the information and documentation requested have not been provided," it read.
The eight-page letter contained 42 questions covering several areas, including private investment in Fifa Forward Enterprise (FFE), the Fifa Peace Prize and the controversial suspended ban given to USA striker Folarin Balogun at the World Cup.
"The withdrawal of FFE, the acknowledgement of mistakes and the announcement of 'potential governance reforms' do not answer how the relevant decisions were taken or why the Fifa Council was not involved at the appropriate stage," it continued.
"Any refusal to disclose information or documents should be justified individually, with a clear explanation of the specific grounds relied upon.
"These questions require answers now. They cannot be deferred until the next meeting of the Fifa Council - nor can future governance reforms substitute for scrutiny of decisions already taken and accountability for them."
Uefa did not specify what action it might take if Fifa fails to respond by the deadline. However, the letter could increase pressure on Infantino ahead of 18 November, when the deadline passes for candidates to declare their intention to challenge him in next year’s presidential election.
The questions were initially raised with Infantino at last week’s Fifa Council meeting, where the president requested that they be submitted in writing.
After the meeting, Football Association chair Debbie Hewitt, who is also a Fifa vice-president, said "if he doesn't answer those questions, he's not fit to be Fifa president".