Officer orders Rihanna review.
Unruly and in some cases drunken fans are thought to have ruined the Stadium of Light gig for many when fights broke out.
Police at the event last month made nine arrests amid reports of disorder. Officers praised the majority of the 57,500 fans who saw the pop star on the Sunderland leg of her Diamonds World Tour.
But now in a meeting with Northumbria Police Commissioner Vera Baird, Chief Constable Sue Sim has said she wants to know what went wrong. It is understood she has requested a formal review of event safety through Sunderland Council.
A police spokeswoman: "We are aware of public concerns around the Rihanna concert. As is standard involving all major events, a structured debrief takes place afterwards and we are currently carrying this out."
A Sunderland AFC spokesman said a safety group reviews every stadium event as part of its standard practice.
STAR OF THE SHOW The singer, Rihanna