Officers engaging in oral sex in a police car is not "official misconduct", a judge has ruled.

The decision comes as a major blow to Queensland police whistleblower Rick Flori's bullying case against his former employer, with his complaint about sexual conduct between two officers not affording him public interest disclosure protection.

Former Queensland Police officer Rick Flori. Credit:AAP

The former Gold Coast sergeant claimed he suffered reprisal after sending a letter to the then-Crime and Misconduct Commission alleging that in late 2009 a female police officer performed a sex act on a male colleague in a police car at a Red Rooster car park.

In the letter, Mr Flori expresses concern about "special attention" given to the female officer.