PC Karen Wade, 26, had claimed she had been "humiliated and victimised" by PC Dean Mountain and Sergeants Paul Fountain and Ian Devey, of West Yorkshire police. Among the allegations, which were dismissed, was that one officer suggested she should have sex with a glue sniffer in the back of a police van.
The tribunal at Leeds unanimously found that Sgt Fountain, 30, did not discriminate against his colleague. In the cases of PC Mountain, 30, and Sgt Devey, 32, the panel decided by a majority that there was no discrimination.
After the judgment the male officers made a short statement through their solicitor, Hilary McLaughlin. "Since August 1995 these officers have been subjected to both an internal and external investigation," Mrs McLaughlin said. "The investigation in 1995 found nothing against these officers. The applicant then sought to bring these allegations into the forum of an industrial tribunal. Again, they have been exonerated."
Ms Wade said after the ruling: "By taking my case to an industrial tribunal and as a result of the vast media attention the case has received, I believe I have given strength to a number of others."
Welfare workers said yesterday that most allegations of sex discrimination failed to reach an industrial tribunal. Most women chose to "grin and bear" it or were advised to keep quiet in case they blighted their careers.
The bitterness of many policewomen was voiced by Sgt Jane McGill, 43, who spoke in support of PC Wade. She told the tribunal: "To be a woman in the police force until recent times has been difficult. I, for my part, have survived that experience for more than a quarter of a century because for a major part of that time I chose to go along with it."
Despite yesterday's judgment, there has been evidence as recently as February that sexism and racism are still a problem in the police service.
A study of 13 forces by HM Inspectorate of Constabulary, while acknowledging that "substantial" progress had been made since its last report in 1992, concluded that a male "canteen culture" was prevalent and "there was evidence of continuing high levels of sexist and racist banter, perhaps more covert and subtle than before, but no less destructive".
Women account for about 14 per cent of the 124,000 police officers in England and Wales.