Police have identified a body found in the River Humber as that of a mother who apparently jumped to her death with her 12-year-old autistic son.
Alison and Ryan Davies were last seen on 11 April
Dental records were used to confirm the body found on 29 April at Welton Waters near Brough in East Yorkshire was that of 40-year-old Alison Davies.
Alison and her son Ryan, from Marple, Stockport, are believed to have leapt from the Humber Bridge on 12 April.
Their family has appealed for help to trace the final steps of the pair.
Detectives said they had gone to great lengths to establish the final few hours of Alison and Ryan's lives.
The pair were last seen on 11 April in Marple, Stockport, at Alison's mother's house.
They were then captured on CCTV arriving at Hull's Paragon Railway Station on 12 April.
CCTV from Hull railway station shows the pair arriving in the city
Ryan's body was recovered from the river on 16 April at Swinefleet Haven.
Police have tried to pinpoint how the pair travelled from the railway station to the Humber Bridge, but inquiries with bus and taxi drivers have failed to establish what happened.
Alison's sister, Lindsay Cook, made a final appeal on Friday to the person who took the pair to the bridge.
She said: "As a family grieving for the loss of our loved ones, Alison and Ryan, we would ask the person or persons who might have seen them on their final journey from Hull station to the Humber bridge to please contact the police with any information they might have.
"No matter how insignificant it might seem to them, to the family it is of great value.
"This last piece of missing information will help us to better understand Alison and Ryan's final moments together and will help us to come to terms with our loss and enable us to put together the last pieces of this tragedy."
Det Supt Colin Andrews added: "The person who drove them to the Humber Bridge is not in any sort of trouble with the police.
"We are not interested if they are unlicensed or have committed any driving offences. All we are interested in is establishing exactly how Alison and Ryan made that journey and I would urge the driver to contact us in confidence at the major incident room."