Financier Amanda Staveley watched Newcastle United's home game against Liverpool.
Staveley – who manages a Middle East investment fund worth tens of billions of pounds – is reported to be looking to buy a Premier League club.
Newcastle owner Mike Ashley made it clear that he wanted to sell in the summer.
Speaking in August, Ashley said: "If somebody would like come along and take this seat and fund Newcastle with a nought on the end with their wealth more than me, I will not stand in Newcastle United's way."
A number of groups have registered their interest in buying United, but discussions are at very early stages.
And there has been no formal contact, up to now, between Staveley and the club.
Staveley watched the Liverpool game, which ended in a 1-1 draw, with Hillsborough campaigner Margaret Aspinall, who was a guest of United manager Rafa Benitez.
The 44-year-old – who was involved in Sheikh Mansour's takeover of Manchester City – was seen heading down the tunnel after the match.
Staveley also attempted to buy Liverpool for Dubai International Capital in 2008, when Benitez was in charge of the club.