The price of being able to place a wastepaper basket on the floor in parts of London is set to hit £10,000 any day now, says estate-agent-to-the-rich Beauchamp Estates.

The firm says that £10,000 per sq ft will be achieved shortly, making Knightsbridge the world’s most expensive residential address.

It means that a 300 sq ft studio would cost £3m.

The £10,000 per sq ft price tag would not be achieved on all properties, but on those that Beauchamp Estates regards as “perfectly presented super-prime”.

It says that such a price, which it expects to be achieved within six months, would set a phenomenal record “unheard of in the global real estate market”.

According to the firm, whose head Gary Hersham featured in the recent BBC ‘Under Offer: Estate Agents on the Job’ series, there is a lack of stock of properties priced at £10m and above.

It also says there has been a “significant” increase in the number of properties let for over £20,000 per month.

Hersham said: “The capital’s property market is outperforming those of rival world cities and London is therefore seen as a lucrative destination for global wealth and investment.

“An ongoing under-supply of good-quality housing has been a key support for London price rises and this looks set to continue.”