An unidentifiable sphere that washed up on a beach in Japan this week has perplexed locals and authorities, sparking a fury of speculation and debate.

Police and the bomb squad were called to investigate the large metal object in the coastal city of Hamamtsu this week.

But – other than it is hollow and doesn’t seem to be a threat – they have been unable to work out what it is.

While many suspect it to be a sort of buoy, the find has fascinated locals, with residents dubbing it “Godzilla egg”. Others said it had clearly come “from outer space”.

Japanese broadcaster NHK showed footage of two officials at Enshuhama beach inspecting the sphere, which is about 1.5 metres in diameter.

Japanese officials cordoned off the beach and ran X-ray exams before deeming the metal sphere to be hollow and no threat.

However, authorities still cannot properly identify the rusted object — which was found by a local who alerted police.

Local authorities said it would soon be removed from Enshuhama beach.

Suspicion around the large sphere comes amid a heightened concern around unidentifiable objects, with the US shooting down a suspected string of Chinese spy balloons earlier this month.

Japan also alleged earlier in February it had identified suspected Chinese spy balloons in its skies at least three times since 2019.

Beijing denies the claims.