A dolphin which was dubbed the 'world's loneliest' after she was discovered at an abandoned Japanese aquarium has died.

The animal, named Honey, died alone after spending the last two years of her life in a small pool at the Marine Park Aquarium in the city of Choshi, east of Tokyo.

She first made headlines around the world after it emerged she had been abandoned in the aquarium along with 46 penguins since January 2018.

Honey and the penguins, along with hundreds of fish and reptiles, were left after the facility was closed, citing a decline in visitors following the 2011 earthquake and Fukushima nuclear crisis.

A dolphin which was dubbed the 'world's loneliest' after she was discovered at an abandoned Japanese aquarium has died. Pictured: Honey the dolphin in the tiny pool at the Marine Park Aquarium in the city of Choshi, east of Tokyo

The animals were fed by an employee but were otherwise left to fend for themselves and spend their time in dirty water.

The female bottlenose dolphin was captured in 2005 near Taiji, a western port town that has become notorious for its annual dolphin hunt that was featured in the Oscar-winning 2009 documentary The Cove.

Her death was reported by the US-based animal charity the Dolphin Project.

The charity said on their website that they had reached out to try to rescue Honey and the other animals, but were not successful.

They said that the dolphin and the aquarium were then sold and so they contacted the new owners to try to buy Honey, so that she could be 'retired in peace and dignity'.

She died alone after spending the last two years of her life in the small pool

However, the Dolphin Project said the discussions ended in March when it became clear that Honey was not going to survive.

The animal then died in her tank on March 29, the charity said.

Photos and videos taken two years ago had shown Honey floating in a tiny pool in the eerily empty facility.

Dust-covered penguins were also seen perching on a crumbling structure near a pile of debris.

News of the abandoned animals spread quickly over social media, with Twitter users posting photos captioned 'Save Honey'.

A resort hotel's offer to give them a new home sparked a flood of retweets.

She first made headlines around the world after it emerged she had been abandoned in the aquarium along with 46 penguins since January 2018

Honey and the penguins, along with hundreds of fish and reptiles, were left after the facility was closed, citing a decline in visitors following the 2011 earthquake and Fukushima nuclear crisis

'I beg the authorities to get in close contact with each other and push ahead with this,' wrote one Twitter user.

The aquarium had an average of three stars out of five on TripAdviser, with many reviewers criticising the park's treatment of the animals.

One reviewer from Norfolk wrote: 'I'm disgusted by the captivity of these beautiful animals. They will have been driven in from out at sea with their pods, seen many of them slaughtered in front of them and then forced into venues like this.

'These dolphins will have been caught in Taiji, ask yourself how they got there. Then ask yourself what kind of life they live stuck in a tiny tank.

'These animals should be swimming wild, not swimming in disgusting water no bigger than a bath tub for people's amusement.'

Another said: 'Although the staff are very pleasant my heart sake when I seen the conditions the Dolphins were being forced to live in. Not only was the water green in colour, it was cloudy as well.'