Over two-thirds of properties in the UK held by overseas shell companies still do not publish information about the identity of their owners, according to new research.
The report by researchers at the LSE, the University of Warwick and the Centre for Public Data found that law enforcement agencies did not even know the true identities of the owners of 35 percent of the properties.
The UK government has previously committed itself to cracking down on anonymous ownership of UK property.
Parliament was on Monday due to consider amendments to the Economic Crime Bill, aimed at closing some loopholes, but the LSE said Prime Minister Rishi Sunak's Conservative government was opposing this.
"We still don't know who really owns tens of thousands of properties in the UK. The government should act to close these loopholes," said Anna Powell-Smith, director of the Centre for Public Data.
The report said the identity of owners was hidden in the cases of 109,000 out of 152,000 properties (over 70 percent) held via overseas companies.
The main reason for "missing or inaccessible information" was the use of trusts, accounting for 63 percent, it said.
The report also highlighted how shortcomings in the register of owners of UK companies -– known as the PSC register -– could also be allowing corrupt practices.
At present, nominees and trustees owning shares are not required to tell UK authorities who they are acting for.
The government is opposing an amendment that would bring transparency to these arrangements, the LSE added.
"The striking thing is that most of the problems with the register are self-inflicted," said Cesar Poux, research officer at LSE's International Inequalities Institute.
"There certainly is some rule-breaking, but most of the problems are because the legislation is flawed."