The 15-metre long Bryde's whale was entangled in an illegal fishing net off Fuerteventura, in the Canary IslandsThis amazing footage shows two young men risking their lives to free a 15-metre long whale after it had become trapped in an illegal fishing net.

Cesar Espino was on a whale and dolphin spotting expedition when they spotted the stricken mammal off Fuerteventura, in the Canary Islands.

The enormous creature, identified as a Bryde's whale, was snared, with its mouth and tail entangled in the illegally set trap, reports Canarias7.

Heroically, he and a friend dived down and Cesar used a knife to cut the net in a daring rescue mission lasting longer than an hour.

Read more: Beached whale saved by fisherman as they drag it into sea with rope

Speaking to reporters, the Spaniard said: "As we approached the fishing line we saw the breathing of the whale and we realised that she was entangled in the net."I quickly jumped into the water and let the whale see me so she knew I was trying to help her.

"I felt compassion for her and didn’t hesitate in freeing her from the ropes."Although Bryde's whales are unlikely to attack humans, the task was fraught with danger because one swipe of its tail could kill a man.

Using only a snorkel, Cesar made several trips down to the whale, first freeing its tail from the netting and then untangling its mouth.The two men described their satisfaction at seeing the creature swim away.

Cesar's pal filmed the drama on January 2 and it has since been uploaded to YouTube, where it has been thousands of times.Viewers have hailed the men "heroes".

Juan Pablo Jiminez wrote: "Congratulations, thank you on my behalf and that of all who love this planet."Another added: "Bravo for the guy, you're a champion. Humanity is not lost at all."

Commonly found in the seas off the Canary Islands, Bryde's whales are filter feeders usually seen at the end of winter and beginning of spring.