This is the heart-warming moment a heroic passer-by plunged into a filthy canal to save a drowning blind dog.

The stray pooch which had lost its eyesight slipped into the deadly water in Bangkok, Thailand - before the man on the pavement above dived in after it.

Dozens of passengers and tourists on a ferry boat watched anxiously as the vehicle came within inches of colliding with the good samaritan.

Onlookers threw him a rubber ring but he shunned the survival aid and passed the dog to safety, hoisting it over his shoulder to people on the ferry. He then swam away before clambering out of the water - still wearing his soaking clothes.

Boat passenger Tibet Nimitput said: ''The man in the yellow shirt is a hero with the heart of gold. The boat driver and ticket collector also showed their kind hearts. It shows all of the good in the world.''

Tibet said it was around 2pm when he decided to go home by canal ferry and saw a crowd gathering by a bridge.

He added: ''We arrived and I saw a man and an old dog floating together in the Saensaeb Canal.

''In the meantime, boat ticket collectors were discussing how to help with boat driver and they decided to pick both of them up to bring them back onto Srinakarindwiroj Prasarnmitr University pier.

''The dog was safe and onboard but the man decided not to get onto the boat and climb back up by himself.''

The dog was checked over by university vets.