Sky Sports understands Aston Villa defender James Collins is having a medical at West Ham ahead of sealing his return to Upton Park.
West Ham have agreed a fee with Villa for Collins and have been given permission to hold talks with the centre-back.
Collins' future at Villa Park has been the subject of conjecture for some time with the Wales international entering the final year of his contract.
Villa are ready to let Collins move on as they close in on a deal for Dutch international Ron Vlaar from Feyenoord.
West Ham have been searching for defensive reinforcements all summer as they prepare for life back in the Premier League.
Collins spent four years at West Ham prior to his move to Villa in 2009 and he will become Sam Allardyce's seventh signing of the summer.