The Sun said the 25-year-old was arrested on Sunday night before being bailed, having previously been questioned over an alleged assault earlier this month
A Metropolitan Police spokesman said: "On Sunday 23 August, officers from Havering arrested a man on suspicion of threats to kill and witness intimidation
"A 25-year-old man was arrested an an address in Emerson Park, Hornchurch
He was taken to an east London police station and bailed pending police enquiries to a date in early October."
A spokesman for the player told the Sun: "Diafra Sakho has not been charged with any offence
He vigorously denies the allegations that have been made against him, and has given police a complete explanation of events.
"He will not be making any further comment."
Senagal international Sakho joined West Ham from French club Metz in August last year and has scored 10 goals for the team in 26 Barclays Premier League appearances.
Source : PA
Source: PA