Moko the dolphin has been internationally recognised after being named on a list of the most heroic animals of all time.

The bottle-nosed dolphin is included in a Time list including a carrier pigeon which helped save soldiers and a Royal Navy cat which solved a rodent problem despite shrapnel wounds.

The list was compiled following a story after the Japan tsunami, where a dog stayed by its trapped canine companion until it was dug out by rescue workers. Moko was ranked eight for rescuing an adult pygmy sperm whale and her calf on Mahia beach in 2008. After many attempts by rescue workers had failed, Moko steered them back out to sea.

Time said the dolphin saved the lives of the whales because, had he not shown up, they would probably have died.

Department of Conservation officer Malcolm Smith, who saw Moko's heroic act, said the honour could not have been more deserved.

"It was a once in a lifetime experience to have seen that. He really was an incredible animal and it's great he made it on to the list."

Mr Smith remembers the day it happened well. "I'd reached that stage of thinking we'd done all we could for these whales, but then up popped Moko who was making a beeline towards them," he said.

"He was making these high-pitched squeaks and squeals and through his body language he guided them back out to sea ... It was an honour to have seen it and I'm glad he's been recognised."

Moko became a national attraction in 2007 at Mahia beach but after two years he moved 80km north to Gisborne's Waikanae beach and its surrounding waterways.

Growing to 3m and 250kg, Moko's thrilled and sometimes unsettled swimmers with his playfulness and imposing physical size.

In July last year, he was found washed up on Matakana Island, next to Mt Maunganui, and the cause of his death is still unknown.

Mt Maunganui documentary maker, Amy Taylor, had followed Moko for the six months leading up to his death and filmed his unusual bond with humans.

"For some reason we think of ourselves as different to animals, but he proved we weren't that different. He had a sense of humour and intelligence. It's great to see those things are being recognised," she said.

"But in my opinion he should be further up the list."

The other animals on the list were recognised for doing things which were instinctual but Moko reached out and helped another species which makes what he did more special, Ms Taylor said.

"He stands out for being really the only one on there for doing something which is outside of his normal behaviour ... he was rescuing another species, not from out of any trained behaviour, but out of his own free will, which I think showed compassion. I think it's quite amazing and he hasn't been given enough recognition."

While filming the documentary, she said she saw how special Moko was and how happy he made people.

"I got to see some of the incredible things that he's done and it shows an amazing level of intelligence and compassion. He wasn't your normal dolphin, he was special."

Peter Cavanagh, who spent nearly every day for six months with Moko as one of his minders, said it was great the dolphin had been recognised.

"It was awesome that he came here. He gave unconditional love and just wanted to play back ... I'm pleased he's been recognised as one of the greats."

Moko was buried at Matakana Island after a memorial service in Whakatane attended by 400 people.