A member of the public came across the firearm at Peacehaven, over the weekend and handed over to police, ITV reports.
According to the BBC, the firearm is in working condition and can fire around 600 rounds a minute but it had no ammunition.
Ownership of an AK-47 is illegal in the UK but according to Chief Inspector Dave Padwick, the firearm was not believed to have been linked to any crimes and they are now carrying out a full investigation to establish its provenance.
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