A judge has ordered a council to make public a list of empty homes after a squatting campaigner challenged its refusal to reveal the list under the Freedom of Information (FOI) Act.
Camden Council argued that disclosing the list could lead to organised crime in and around the properties.
However, the judge said any concerns were outweighed by the public interest in returning empty properties to use.
Camden has 28 days to comply with the FOI request.
The ruling was a victory for Yiannis Voyias of the Advisory Service for Squatters.
Mr Voyias argued that making the list public would "rejuvenate the empty homes debate" and put pressure on the government to tackle empty property.
He said academic researchers, homelessness charities - and even English Heritage - would benefit from disclosure of the number and location of unoccupied homes.
Camden's lawyers argued the disclosure of the list would compromise "the prevention or detection of crime".
Local police, who are backing the council's stance, said there was a link between squatting and crimes, including vandalism, running crack houses and threatening behaviour.
Camden also pointed out that, after a list of long-term empty homes in Lambeth was made public, the number of squatted properties in that borough almost doubled.
Under the ruling Camden will have to release information on all empty council owned properties and on private properties owned by a non-individuals that it knows to be unoccupied.
Judge Fiona Henderson accepted that disclosure of the list was likely to have "a negative impact on the prevention of crime".
But she said there was a lack of evidence that squatters were the source of more anti-social behaviour than rent-paying tenants.
She also emphasised the fact that squatting "is not illegal".
In a statement, Camden said it was considering its legal options.