Police dog Resi and her handler PC David Lowry had been called to locate a wanted man who had fled from a stolen BMW in Bramley.
With the assistance of the police helicopter, Resi managed to chase and capture the wanted man by grabbing onto his right arm.
What she didn't know was that the man's jacket was covering a pot on his arm from an injury meaning Resi could not hold onto him properly.
The criminal, taking advantage of this, repeatedly punched Resi before hurtling her through the air and into the River Aire.
PC Lowry said: "Our dogs are trained to bite the right arm and Resi did just that, but we didn't know he had broken his right arm and had a pot on it under his jacket. So, as Resi has bitten the pot, there has been nothing for her to grip hold off.
"He was punching her but she wouldn't come off and then he has spun around and flung her and she has just flew through the air and landed in the River Aire.
"At the time I thought I saw her fly through the trees and then the helicopter radioed me and told me they thought he had thrown her in the river."
PC Lowry raced to check if Resi was OK.
"I called her and she came back out of the river to me," he said.
"I could tell she was lucky and hadn't been injured by the way she climbed out of the river.
"I had a think about what to do next. Because she had had that incident, I did question that if I sent her again, she might not do it, and I couldn't blame her to be fair. If it was me, I wouldn't."
PC Lowry made the decision to send Resi to capture the man again.
By this time he had gone across the river and onto an island.
"Resi wasn't even bothered in the slightest," PC Lowry said.
"She ran down the bank where he had and straight across the island.
"He presented his arm with the pot on to her again and she has bitten it, like she would do in training.
"She has had a bit of a fight with him on the island and then I have come across and we managed to get him down.
"Resi had hold of one arm and he put up a struggle, but I handcuffed his left arm to a tree root, put her on the lead and managed to arrest him.
The man was later charged with a number of offences and sentenced to two years and eight months in prison following the chase in May, last year.
Both PC Lowry and Resi were nominated for a bravery award at the recent West Yorkshire Policing Awards.
The pair have been working together since September 2016 and have built up a close bond.
PC Lowry said: "You spend that much time with these dogs and for me it was like he had injured one of my kids.
"As soon as she came out of the river, there was no way he was getting away. One way or another we were going to catch him.
"Resi and I spend a lot of hours together and you do get really attached."