Not since Moby Dick has a mysterious white whale proved so elusive.

And now it appears Benny the Beluga whale has left for good.

Native to the Arctic, the beluga whale grabbed headlines when it turned up in Thames near Gravesend last September, and a string of sightings were reported over the following months.

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But those reports diminished over the winter, with experts speculating that Benny had travelled east of the town - and he is now believed to have made his way out to sea on the trail of migratory fish.

The Port of London Authority issued an "update on the whale", stating: "The last confirmed sighting of the whale was in December 2018, further downstream from Gravesend.

"Hydrophones have been placed in the water and can record noise produced by the whale - these have also not recorded any evidence of whale activity.

"As the fish that were likely to be the preferred food source for the whale migrate out of the estuary early in the year, we conclude that the whale has moved on elsewhere."

Benny's leaving will be a sad end for some - his presence in the Thames sparked a surge in visitors, prompting traders to begin marketing Beluga themed merchandise and leading Gravesham council to cancel the town's fireworks display due to concerns for the whale's welfare.

At the time Gravesham Council said every effort would be made to reschedule the event but that a decision could not be made while Benny was in residence near Gravesend.

But the council now says a fireworks event will not be held until November's scheduled display.

Melanie Norris, Director for Communities said: “We hope that Benny is safe and well and on his way back home, wherever that may be.

VIDEO: Experts say Benny appears to be healthy

"Now that we are in the summer months the evenings are much lighter and so we will not be having the fireworks event until November.

"The sponsors of the fireworks have agreed to put their money towards additional activity at The Riverside Festival on July 6, which will have entertainment throughout the day for the whole family including a vintage event in the Fort Gardens and, for the first time, a week-long Festival fringe festival."

While that might be a disappointment for fireworks fans, if Benny's welfare is the primary concern then his return to the sea can only be a happy ending.

Read more: All the latest news from Gravesend