West Ham have asked the Italian Football Federation to suspend their former striker Alessandro Diamanti's registration with Brescia.
Diamanti left Upton Park to join the then Serie A side in August 2010, but the latest instalment of the £2 million transfer fee has not been paid, according to the Hammers.
A statement from West Ham read: "Due to the failure of Brescia to pay the latest instalment fee, West Ham have asked the FIGC (Italian Football Federation) to suspend the player's registration and requested that the national association and FIFA impose sporting sanctions until the matter is resolved.''
Diamanti spent a year with the Hammers after joining from Livorno, hitting eight goals in 30 matches. He has since scored six goals in 31 appearances for Brescia and earned his first Italy cap.