West Ham have signed former Manchester City midfielder Abdul Razak on a short-term contract from Russian side Anzhi Makhachkala.
Razak, 21, who has won five caps for Ivory Coast, began his career at Crystal Palace before joining City.
But he did not start a Premier League game and had loan spells at Portsmouth, Brighton, Charlton and Anzhi, joining them on a full-time deal in October.
The signing is Sam Allardyce's fourth of the January transfer window.
West Ham, who are 18th in the Premier League, have also signed three players on loan this month - Wolves defender Roger Johnson,Roma striker Marco Borriello and AC Milan midfielder Antonio Nocerino.