This CCTV footage shows the last moments of a healthy three-year-old girl who died from a mysterious head injury.
Mariam Alam, three, died in hospital in November 2011 from severe head injuries.
She was caught on camera around 20 minutes before paramedics were called to her aunt's house in Coventry, walking with her mum in a Lidl store in the Foleshill area of Coventry. She was wearing a red coat and white tights.
A man, 35, and two women, aged 32 and 25, were questioned by police but no one has been charged over her death.
A police investigation was launched when a post-mortem found Mariam had died from a significant head injury, which no one can explain.
Police have been met with a wall of silence from the community, and conflicting witness statements.
Detective Inspector Hanson, from the public protection unit, said "Less than 20 minutes after this CCTV image was taken in the nearby Lidl supermarket, Mariam was on the brink of death.
"We have built a picture of what was going on at the time but we're still not sure where she was, whether she was deliberately hit or whether she had a fall.
"That's why, 12 months on, I'm appealing to anyone with information, no matter how insignificant it may seem, about Mariam or what happened to her on the day she died to come forward.
"We're specifically appealing for an anonymous male caller, who phoned police in January this year with information that led to two arrests, to get back in touch with the inquiry team."
Anyone with details about Mariam's death should call Coventry Police's public protection unit on 101 or Crimestoppers anonymously on 0800 555 111
MORE:Advice and health