Former England rugby player Tom Voyce is believed to have died after going into the River Aln in his car on Sunday, Northumbria Police said.
The force said officers received a report on Sunday morning that Mr Voyce, 43, who played for clubs including Bath and London Wasps, had not returned home following an evening with friends.
Northumbria Police said it is believed he attempted to cross Abberwick Ford in his car which has then been pulled along with the current of the river.
The car has since been recovered but officers did not find Mr Voyce and it is believed he was swept away while attempting to escape and has died.
Chief Superintendent Helena Barron, from Northumbria Police, said: “This is an extremely tragic incident, and our thoughts are very much with Tom’s loved ones at this time.
“Our officers continue to support his family and we would ask that their privacy is respected.
“Extensive inquiries have been ongoing since concerns were raised for Tom, including deploying specialist teams to search for him.”
Northumbria Police said the heavy rain brought by Storm Darragh played a part in raising the level of the River Aln over the weekend.
The force has deployed specialist officers from its marine section alongside the National Police Air Service, drones and dog handlers in the search for Mr Voyce, while volunteers from the North of Tyne Mountain Rescue have also been looking, joined by members of Mr Voyce’s family and friends.
Ms Barron added: “Our searches continue but we are dealing with very challenging circumstances in trying to recover Tom.
“This is down to the conditions, including the river flow and the level being significantly heightened due to the exceptionally heavy rain we experienced over the weekend.
“Sadly, we can therefore not provide any timescales around this.
“We would like to thank our colleagues from Mountain Rescue for their continued support and all those who have helped with the searches.”