London's City Hall has blocked a contract worth up to £50 million between the Metropolitan Police and US technology company Palantir, preventing the deployment of the firm's data analytics software for law enforcement purposes.

The rejected deal would have provided Palantir's software systems to the Met Police, though specific details about the intended use of the technology were not disclosed. Palantir specializes in data integration and analysis software used by government agencies and large organizations.

The decision comes amid ongoing scrutiny of Palantir's work with various government agencies. The company has faced internal employee concerns regarding its contracts with immigration enforcement agencies, prompting the firm to develop new user-auditing tools through internal hackathons.

Palantir's software is currently used by multiple government departments and agencies across different countries for data analysis and intelligence purposes. The company has been expanding its public sector contracts while simultaneously addressing criticism about transparency and oversight of its technology deployment.

The Mayor of London's office has not provided detailed reasons for blocking the contract, and neither the Metropolitan Police nor Palantir have issued public statements regarding the decision. The rejection represents a significant setback for Palantir's expansion into UK law enforcement technology services.