Trading standards officers are warning whisky drinkers that counterfeit Johnnie Walker Black Label could poison them.

Brighton and Hove City Council issued the warning following a discovery by the Food Standards Agency of more bottles contaminated with unacceptable levels of methanol.

The counterfeit bottles, found in Berkshire this week in a joint operation by Customs and Excise and police, are similar to 50 bottles of counterfeit Johnnie Walker found in Hackney, London, in November last year.

The most recently discovered counterfeit bottles do not have any neck labels. Last year's bottles had neck labels saying 'distilleries', whereas the neck labels on genuine bottles say 'distillers'.

Drinking contaminated whisky could cause methanol poisoning. Symptoms include severe stomach pain, drowsiness, dizziness and blurred vision, leading to blindness.

Rolls of counterfeit labels for Highland Pride whisky were also discovered in the same place as Johnnie Walker whisky, which suggests that counterfeit bottles of this whisky might also be on sale.

If someone thinks they may have a counterfeit bottle, they should call Brighton and Hove City Council's trading standards team on 01273 292523.