A New Zealand octopus called Inky has become a media star after an ingenious escape from the national aquarium, his former keeper says.

Inky’s daring late-night break-out has featured on CNN, Time Magazine and on National Geographic, the Napier City Council said on Thursday.

In January, keepers found his tank empty and the grill on top ajar.

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Following a damp trail across the floor to a drain pipe, they surmised that the sneaky cephalopod squeezed down the pipe to the Pacific Ocean and freedom.

Napier City Council communications manager Robyn McLean said she was not too surprised by the global interest in Inky’s story.

“Everyone loves a great animal story and this certainly is one of those,” she said.

“His intelligence is the surprising element for a lot of people, the fact that he could squeeze out of a tiny hole, he took the opportunity to do it at night when there were no staff around, made it down a two-metre wall, across the floor and down a drain that just happened to have a reticulated flow out to the Pacific Ocean.

“I mean it’s genius.”

Because octopuses have no bones except their beak they can fit into extremely small spaces. They are very intelligent and have been known to use tools.

Inky had been at the aquarium for about a year after being brought in by a fisherman who found him caught in a crayfish pot.

“He wasn’t in a very good condition. He had lost a few tentacles so we were rehabilitating him and then he just stayed.”

McLean said Inky had not previously tried to escape, but was obviously smart.

“The staff would play games with him to keep him entertained and if you put your hand up to the tank he would often come up and put his tentacle up on the side like a high five.

“Maybe he just felt that he was healed and the time was right for him to go back to where he came from.”

The aquarium’s remaining octopus Blotchy was not expected to become lonely after Inky’s escape as the two were not tank mates, she said.

She also said security would be tightened.

“We are not sure whether the mesh on the top of Inky’s tank had been left ajar slightly or whether he had pushed it up – because they are quite strong.

“But this really was a pretty incredible escape. It seemed everything lined up for him to make it work.”