"Shooting Dogs," funded by the BBC and backed by the Rwandan government, was filmed on location -- which aid organizations criticized as insensitive to survivors of the 1994 atrocities, The Observer reported Sunday.
Genocide survivors were used as extras and crew, the newspaper said.
The violent scenes caused some students at a nearby school to suffer flashbacks and one crew member suffered a breakdown on the set, the newspaper said.
"In Rwanda, if you see a machete being wielded it doesn't matter if it's for a film -- it seems real," Mary Kayitesi Blewitt, of the British-based Rwandan charity Survivors' Fund, told the newspaper. "When the shoot was over, we had to step up trauma counseling.
"It took some people six months to overcome the anxiety, fear and paranoia."
"Shooting Dogs" is due to be screened in Kigali this month.