1 / 7A senior officer in Hong Kong police's National Security Department has been placed on leave after he was caught in a raid on an unlicensed massage parlour, say local media reports.2 / 7Reports have named him as Director of National Security Frederic Choi.3 / 7According to news site SCMP, visiting an unlicensed parlour is not an offence but could 'damage the force's image'.4 / 7This is the first big scandal to hit the unit after it was set up to enforce the city's national security law.5 / 7Thousands in Hong Kong protested last June when the national security law was implemented.6 / 7The law criminalises secession, subversion and collusion with foreign forces with the maximum sentence life in prison.7 / 7However, Beijing has said it will target 'sedition' and bring stability. Since the law was enacted around 100 people - including prominent pro-democracy activists - have been arrested. Hong Kong police told BBC Chinese in a statement that they were investigating 'an allegation of misconduct by a police officer', adding that the person involved had been placed on leave while the investigation continues. 'The police attach great importance to the conduct of police officers... [we] will conduct a fair investigation,' it added, though it declined to give further details on the incident or name the person involved.