Vodka drinkers have been warned to check the labels of bottles they have bought after a batch containing a highly toxic chemical was found for sale on the streets of London.
Customs officers seized 480 one-litre (1.76-pint) bottles of Original Russia Export Quality brand vodka containing large quantities of methanol from shops, pubs and off licences in Newham on Tuesday and Wednesday.
Police are worried some bottles may remain on sale or may already have been sold.
Anyone who thinks they may have drunk any should seek immediate medical advice.
A few teaspoons of methanol can cause blindness, tablespoons can kill.
Also known as methyl alcohol, the simplest form of alcohol, it is used as anti-freeze and a burning agent in paint thinners, varnishes and glass cleaners.
Blurred vision
Symptoms of methanol poisoning can be delayed for several hours.
They include breathing difficulties, abdominal pain, blurred vision, dizziness and drowsiness.
Anyone who sees a bottle of the vodka, made in Belgium, or knows how it reached Newham should call the police.
Customs also uncovered an estimated £2m in takings on which around £400,000 in VAT had not been paid.
No-one was arrested during the raids on Wednesday and Thursday but a Customs spokesman said charges may follow in relation to VAT evasion and trading standards offences.