Tottenham have filed High Court proceedings against Manchester United co-owner Sir Jim Ratcliffe's company Ineos Automotive.
Court records show Spurs filed a commercial claim over a terminated sponsorship agreement, though no documents are available.
Ineos Automotive, a part of Ratcliffe's conglomerate of Ineos businesses, agreed a five-year deal with Spurs in 2022 - before Ratcliffe bought a stake in United.
It meant that its Ineos Grenadier car became the London club's official 4x4 vehicle partner.
An Ineos statement read: "Ineos Automotive has been a partner of Tottenham Hotspur since 2022, expanding on a partnership agreement that Ineos Group had in place with the club since 2020.