Police, fire and ambulance crews were called to the riverside near Ashbridge Nursery in London Road, Preston at around 7am.
The fire service launched its rescue boat to search the Ribble and the police helicopter was deployed.
The wanted man has now been named as 30-year-old Daniel Godkin.
He was seen leaping into the freezing water after being chased by officers and it is believed he swam across to the other side where he made his escape.
He remains missing and Lancashire Police continue to search for him.
You can find more details on the search for Godkin here.
These were the scenes as the search got under way today...
1. River Ribble search
The fire service launched its rescue boat to search the River Ribble Photo: Michelle Adamson
2. Wanted Man
Police are trying to find Daniel Godkin, 30, after he made off from officers and jumped into the River Ribble in Preston this morning (Friday, January 13) Photo: Lancashire Police
3. River Ribble search
There are fears for the man’s welfare due to the strong current and cold temperatures in the Ribble Photo: Michelle Adamson
4. River Ribble search
Police, fire and ambulance crews are conducting the search from the the riverside near Ashbridge Nursery in London Road Photo: Michelle Adamson