The Occupy London activist group has claimed to have taken over another site in the city's financial centre, but the building's owner has warned it is unsafe.

According to the protesters, they have "publicly repossessed" Roman House, an abandoned nine-storey office building in the Barbican in the City of London which previously housed companies from the financial service industries.

Around 20 demonstrators are said to have moved into the building in the early hours of Saturday morning.

In a statement on their website, Occupy London said they would remain in the building until such time as the City of London Corporation publishes full details of its City Cash Accounts.

"This is a request that Occupy London has consistently asked off the Corporation, so that it can become a more transparent public body like every other public body in the country," the statement read.

On Wednesday the High Court ruled that the original protest in the capital outside St Paul's Cathedral, near the London Stock Exchange, should be evicted.

Occupy supporter Bryn Philips said the Corporation had "undermined our democracy" through the power of its lobbyists and must "submit to public scrutiny".

"If the City agrees to publish its City Cash Accounts, future and historic, we will leave the building immediately. If does not, we will take appropriate action until such time as it does," he said.

According to the protesters the City of London Police have visited the building and have agreed that it is a civil matter.

But Berkeley Homes, which owns the building, described the occupation as "potentially dangerous".

A spokesman said: "We urge the protesters to vacate this building site as quickly as possible as we are very concerned that they are putting both themselves and members of the public in real danger.

"It is not safe for public use, there are holes in the floors and we are in the early stages of asbestos removal.

"The protesters are misguided in their actions, which are sadly preventing Berkeley Homes from implementing their planning permission and so providing not only 90 much-needed new homes, but also a significant number of key construction jobs during an economic crisis."