London housing
Rent prices in London for the Olympics period are very high (Reuters)

London's housing crisis is being made worse by the 2012 Olympic Games, a housing charity has warned.

The capital's already expensive lettings market may see prices soar even higher as private landlords seek to cash in on the games.

"Londoners living in the Olympic boroughs are already suffering from increasingly unaffordable rents, a lack of stability and a minority of rogue landlords who exploit the high demand for homes in the capital," Campbell Robb, chief executive at Shelter, said.

"We are seeing signs that the Olympics are exacerbating these problems with some landlords looking to evict tenants in order to re-let their homes to capitalise on Olympic visitors."

London was already in the grip of a housing crisis regardless of any Olympics-related problems, Robb said.

"Unless London's mayor starts to prioritise housing and invest in the decent, secure and affordable homes that Londoners desperately need, these problems are going to exist long after the games are over."

Recent research by Gumtree, a website offering lettings, shows that short-term rental prices for the Olympic Games period are up 445 percent on the same month the previous year.

A quick search on the website shows the prices being demanded for some properties in and around London during the Olympics period.

A one-bedroom house in Romford, Essex, which the advert claims sleeps four people, is advertised at £1,250 a week - a whopping £5,000 a month.

Similar properties in the area are usually around £600 a month.

Another one bedroom property, this time in Walworth, asks for £1,200 a week.

Ordinarily rent for a similar flat in the area is around £200 a week.

The government expresses concern over the possibility of contracts being cut short and tenants thrown out so landlords can make a lot of money from the games - though it said nothing about the dramatic rental price increase.

"The message to landlords is that unlawful eviction of tenants is a criminal offence, and those found guilty could face a two-year prison sentence," a spokeswoman for the Department for Communities and Local Government said.