West Ham United have confirmed they will be taking legal action against Portuguese side Sporting Lisbon.
Both sides have been embroiled in a bitter war of words following the summer transfer window, in which speculation grew surrounding a move for midfielder William Carvalho.
In the aftermath of the window closing, Sporting's director claimed an offer was never made by the east London club.
The news wasn't taken kindly by the Hammers, who will now take legal action against the Primeira Liga side.