The police watchdog is to investigate a force's handling of a 12-year-old girl's drowning.
Shukri Yahye-Abdi died after going into the River Irwell in Bury on 27 June.
A complaint against Greater Manchester Police alleges officers ended investigations too early and treated relatives differently because of their ethnic background.
The Independent Office for Police Conduct (IOPC) is leading the investigation.
It is alleged the force failed to conduct an effective investigation and prematurely concluded Shukri's death was not suspicious.
Shukri's family have said they do not believe her death was an accident, and that it was out of character for her to play near water because she could not swim.
Following Shukri's death, her school, Broad Oak College Sports in Bury said it would review its anti-bullying policy.
But Det Insp Andrew Naismith told an inquest there was nothing to suggest any bullying or coercion took place.
IOPC regional director Amanda Rowe said: "I am aware that the circumstances of Shukri's death are a concern to many, not least because there are many unanswered questions about how she came to be in the River Irwell that day.
"That is a matter for Greater Manchester Police and the coroner."
A separate investigation into her death by Greater Manchester Police is continuing, the IOPC said.