The tribunal ruled that the force could not be held liable for an employee's alleged act 'done outside the course of his employment'. The alleged rape 'would not amount to a contravention of the Sex Discrimination Act'.
Constable Eileen Waters, 24, had made a claim against the force for compensation for victimisation under the Act. She may now sue it, or individuals, for damages.
In the early hours of 15 February 1988, the tribunal heard, PC Waters, then 20 and in the force for less than a year, was allegedly seriously sexually assaulted by a constable in her quarters above Marylebone Police Station.
Monica Carss-Frisk, for the Metropolitan Police, said that because the alleged sexual assault was the 'focus' of the action, PC Waters 'must be able to show that the assault would have been an act of discrimination by her employer by subjecting her to some detriment'.
Because the alleged assault took place at PC Waters's home, when she was off duty and her alleged assailant was on sick leave, Miss Carss-Frisk said, the 'unauthorised' act was 'not in his employer's time, not for the benefit of the employer . . . outside the sphere of his employment'. To say that the force was liable for such an act was tantamount to saying that an employer would be liable for 'an employee who committed a murder when on holiday'.
Sarah Maguire, for PC Waters, said it was PC Waters's complaint about the alleged assault, not the assault itself, 'which led to the victimisation' and formed the basis of the action. The tribunal, therefore, did not have to decide whether the alleged assault constituted an act of discrimination under the Act nor whether, if it was discriminatory, her employers were liable.
Denis Brayden, the tribunal chairman, said the Sex Discrimination Act 1975 'does not make the employer vicariously liable because the act done by the police officer was not done in the course of his employment'. The claim that the force had 'punished PC Waters because of the original complaint . . .' must fail, he said, because PC Waters 'has not alleged an act that would amount to a contravention of the Act'.
Outside the tribunal, PC Waters wept and said she had been 'disgracefully' treated by officers. It was 12 weeks, she said, before an internal Scotland Yard investigation began. The alleged rapist was not suspended. After the Crown Prosecution Service decided that he should not face charges, he was not disciplined and is still serving in the force.
She claimed investigators had been unsympathetic and aggressive, and she was told to resign. She claimed her attempts to get new qualifications to gain promotion were blocked.
In July last year, she was moved from a specialist search team to the property office. She is now on sick leave considering her future in the force.
Scotland Yard said last night it was 'regrettable' that PC Waters chose to take the matter to an industrial tribunal 'after considerable efforts were made to resolve the officer's grievance' - adding it hoped she would resume her career.
'The allegations of sexual assault were thoroughly investigated at the time. Decisions whether or not to proceed with criminal charges are taken by the Director of Public Prosecutions, as is always the case where allegations of crime are made against police officers. In this case, they did not recommend prosecution,' a spokesman said.