The man missing in the River Tees has been named as Wadud Abdul from the Westgate Road area of Newcastle.
Mr Abdul who is a teacher at The Hadrian School in Benwell was enjoying a family day out at Low Force near to Middleton-in-Teesdale yesterday, his 36th birthday, when he decided to go swimming.
After jumping into the river he appeared to get into difficulty. Emergency services were alerted at 3.30pm and an extensive search operation began.
Durham Constabulary along with the fire and ambulance service and with assistance from Teesdale and Weardale Search and Mountain Rescue Team are continuing with the search this afternoon.