Ken Bates has become the latest figure in football to take legal advice on the implications of the Carlos Tevez affair for his club.

The Leeds United chairman believes that Sheffield United's relegation in 2007 actually cost their Yorkshire rivals £500,000 in sell-on clauses written into the contracts of three players they sold to the Blades.

They would have been invoked had Sheffield United stayed in the Premier League and Bates believes the Blades could now be liable to pay the money after they reached an out-of-court settlement with West Ham worth about £15million.

Leeds's case is based on the sales to Sheffield United of Rob Hulse for £2.2m, Matthew Kilgallon for £1.75m and Ian Bennett's free transfer.

Bates said: "When they got relegated we missed out on a substantial sum. That's what we lost and if they are being compensated for their loss, we should be compensated for ours" Leeds would not be seeking money from West Ham, but former Sheffield United manager Neil Warnock and some of his players may pursue private claims.

Upton Park officials have said they will fight any action and see the continued speculation over litigation a bad for the game.

"It is now becoming clear that the ruling [by the arbitration panel] has encouraged a potentially endless legal chain of claims and counter-claims, which can only be damaging to English football," said West Ham in a statement.

"We will resist any attempts to prolong this matter through the courts."