The 25-year-old was held by police officers last Thursday and questioned in Tower Hamlets and has been bailed until September.
The Senegal international started West Ham’s 2-0 win over Arsenal on Sunday and proved a real success in his debut season at Upton Park.
Sakho was brought in by Sam Allardyce last August from Ligue 1 side Metz and went on to bag ten goals in 20 starts in 2014/15.
Scotland Yard released a statement in relation to the arrest;
“Officers from Tower Hamlets have arrested a man on suspicion of domestic assault.
“The 25-year-old was arrested on Thursday, 6 August at an address in Emerson Park, Hornchurch.
“He was taken to an east London police station and has been bailed to a date in late September.”