Operation Spanner was a police investigation into same-sex male sadomasochism across the United Kingdom in the late 1980s. The investigation, led by the Obscene Publications Squad of the Metropolitan Police, began in 1987 and ran for three years, during which approximately 100 gay and bisexual men were questioned by police. A resulting House of Lords judgement, R v Brown, ruled that consent was not a valid legal defence for actual bodily harm in Britain.