West Ham United reportedly have proof that they made at least one offer for Sporting Lisbon midfielder William Carvalho during the summer transfer window.

During the closing weeks of the season, the Hammers were heavily linked with an approach for Carvalho but despite talk of a move, the Portuguese international eventually remained with his current club.

Sporting Lisbon communications chief Nuno Saraiva has denied suggestions that West Ham made a club-record bid for Carvalho, but it appears that the Hammers did lodge an offer on August 11, after initially stating their intention to make a bid a day earlier.

According to Sky Sports News, the Premier League club made an offer of €25m (£22.8m) payable in three installments, plus a number of add-ons which needed to be negotiated.

Carvalho has a release clause inserted into his contract, and it was alleged that Sporting would not agree to sell the player unless that figure was met.

West Ham co-chairman David Sullivan has already stated that he is considering legal action over claims that an offer was not made.