The BBC says it has received video footage showing police in Myanmar standing by as Buddist gangs attack and kill Muslims.
The footage was filmed by police in the town of Meiktila in the Mandalay region during several days of violence in late March that left at least 43 people dead.
The video is remarkable for the comprehensive way it documents the violence and because much of it was shot by police, the BBC reports.
In the sequence where policemen look on as a man rolls on the ground having been set on fire, the watching crowd are heard to say, "No water for him - let him die".
Another sequence shows a young man attempting to flee and getting caught, after which he is beaten by a group of men, which includes a monk. A blow with a sword strikes him and he is left on the ground, presumed dead.
Only in one shot are the police seen escorting Muslim women and children away from their burning homes.
The release of the video comes before a decision by the European Union this week on whether to permanently lift sanctions on the southeast Asian country in response to recent reforms.
Sanctions include the freezing of assets of more than 1000 Myanmar companies, travel restrictions on officials, and a ban on EU investment in many areas. However, an arms embargo is expected to remain in place.
The move is a response to political change under President Thein Sein, who came to power after elections in November 2010. His administration has freed many political prisoners and relaxed censorship.
Aung San Suu Kyi, who was under house arrest for many years, leads a pro-democracy opposition which has a small presence in parliament.
