A black police officer was passed over for promotion because of his race, an employment tribunal found.

Pc Ronnie Lungu won a claim of racial discrimination and harassment against Wiltshire Police.

He had alleged his ratings in assessments were downgraded in order to make him appear unworthy of being given a permanent sergeant's role.

The Bristol tribunal panel's ruling said: "The reduction in the scoring has the very significant effect in terms of making it appear reasonable that the one black applicant for promotion was scoring lower than the 19 white applicants and should therefore not be promoted."

Mr Lungu, 40, who joined the force in 2003 after moving to England from Zimbabwe, was also said to have been subject to derogatory comments.

Following the judgement, he said: "When I realised I was being singled out and treated badly because of the colour of my skin, I felt so angry and upset.

"I had worked all my career to serve the community and be the best police officer I could, but I was being penalised because I was black. It was totally unacceptable.

"But what made matters worse was that when I did raise the issue internally, it wasn't taken seriously."

Mr Lungu added: "I joined the force to uphold the law and I still would like to remain with the force.

"I need reassurance from Wiltshire Police that they will take issues of discrimination seriously in future and I want to see new procedures put in place to tackle discrimination and better education among senior members of staff in how to deal with complaints."

Mike White, chair of Wiltshire Police Federation, said the judgment "sends a stark message to Wiltshire Police".

He added: "It takes special people, like Ronnie Lungu, to stand up and challenge such behaviours and I applaud his bravery in doing so."

The claimant's lawyer Juliette Franklin, of Slater and Gordon, said: "It's extremely disappointing that people are facing this sort of prejudice and discrimination.

"Wiltshire Police needs to take this tribunal ruling very seriously and take swift steps to address any failings which have been identified."

Wiltshire Police chief constable Patrick Geenty said the force is taking the matter "very seriously" and spoke of his concern at the findings.

He said: "Clearly, the issues this raises do need to be carefully considered. We continue to work hard to embed our values and behaviours and the Code of Ethics within the organisation.

"Wiltshire Police will learn lessons from this process and continue to move forward."

He said Wiltshire Police has a "very small number" of black and ethnic minority staff, with 16 officers, 15 police staff and three special constables.

Mr Geenty added: "This judgment raises some serious concerns about how an officer felt he was treated.

"I have no doubt that this judgment will affect members of the Black and Ethnic Minority community who might be considering joining Wiltshire Police. I want to reassure the public that Wiltshire Police are committed to increasing diversity in the Force so that we can reflect the communities we serve."

Any compensation payout due to Mr Lungu will be determined at a later hearing.