Former England rugby player Tom Voyce, 43, is believed to have died after going into the River Aln in his car, Northumbria Police said.
The force said officers received a report on Sunday morning that Mr Voyce, who played for clubs including Bath and 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, which had been running high due to severe weather in Storm Darragh.
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.”
The search has included specialist officers from the force’s Marine Section, the National Police Air Service, drones and dog handlers.
Volunteers from the North of Tyne Mountain Rescue have also been searching alongside Mr Voyce’s family and friends.
Chief Supt 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.”
Members of the public are asked not to attend the scene to conduct their own searches.
The spokesperson said Voyce’s wife Anna and all his family have expressed their gratitude for all the help and support from the police, friends and the local community in helping find Tom.
Voyce won nine caps for England during his career and spent six years at Wasps, from 2003 to 2009, where he helped them win European and domestic titles, moving there from Bath and then leaving to join Gloucester in 2009.
He made a total of 220 Premiership appearances before retiring in May 2013.
England Rugby posted on X, formerly known as Twitter, saying: “Our thoughts and prayers are with the family and friends of Tom Voyce at this extremely challenging time”.
Gloucester Rugby also posted on X saying: “Gloucester Rugby is desperately sad to hear the distressing news regarding our former player and friend, Tom Voyce.
“Our thoughts and prayers go out to Tom’s family and friends at this incredibly difficult time.”
