You've had the £30 burger, £100 fish finger, £500-a-kilo mushrooms and even the £28,000 truffle. The latest ultra-expensive consumable coming to Britain is a tiny £40 bottle of water beefed up with liquid oxygen.

Oxyshot, described as a 'maximum performance extreme oxygen supplement', promises users the sort of 'high' that millions seek from energy drinks, illegal drugs and cups of strong coffee.

The highly oxygenated liquid is being targeted at everyone from Premiership footballers to stressed employees. Created in Australia, it is being launched this week in Birmingham.

At £40 for 250ml - less than in a normal canned drink - it is pricier than the most expensive champagnes. But Riley points out that users need only 10ml, or two capfuls, once or twice a day to experience a significant increase in their energy level - or £1.60 a shot.

It tastes like chlorinated water from a swimming pool and can be taken either watered down or with juice. Alternatively, those brave enough can gulp it straight. Its maker says it contains contains bio-available diatomic oxygen, a small dose of Atlantic sea salt and deionised water, and that the extra oxygen is pumped into the water using 'Nasa-based technology'.

It will be sold in Britain initially on the internet in two forms: 'sports oxyshot', at £39.99 for 250ml, aimed at sportspeople; and 'oxygen 4 life', at £36.99, as a tonic.

UK Sport, which drug-tests athletes, said: 'Extra oxygen can potentially enhance sporting performance, so it could be useful.'

But Robert Dawson, a GP in Co Durham and an expert on performance-enhancing substances, said: 'The idea of getting extra oxygen through a drink doesn't add up. People get oxygen through their lungs, not their stomach. I can't see extra oxygen taken this way making a huge difference to anyone. People looking for an energy boost from this will probably be disappointed.'