The ICC said it took the findings very seriously. The MoD has said the allegations are unsubstantiated.
The year-long investigation claims to have found evidence of murders by an SAS soldier, as well as deaths in custody, beatings, torture and sexual abuse of detainees by members of the Black Watch.
A senior SAS commander was referred to prosecutors for attempting to pervert the course of justice, the investigation claims.
Operation Northmoor was set up by the government in 2014 and looked into 52 alleged illegal killings.
Its closure was announced by the government before Royal Military Police detectives even had a chance to interview the key Afghan witnesses.