The research, conducted by the Police Superintendents’ Association of England and Wales, surveyed 1300 senior officers.
Of those who identified as gay or lesbian, 4 in 10 revealed that had “experienced discrimination in the policing workplace”, with some admitting that homophobia exists at “a subtle underlying level” in their force.
One officer said they “would love to be openly gay”, but felt like the workplace culture would prevent them from being so.
Metropolitan Police Chief Superintendent Mike Gallagher, who oversees LGBT issues for PSAEW, said: “The fact that 40 per cent of our gay and lesbian members have experienced discrimination in their careers is frustrating and unacceptable.
“It is very disappointing that we are still talking about this as an issue in 2014. We need to do better. And we can.”
“It must be emphasised that homophobia is not accepted in policing.
“The police service has come a long way, as has society, and that has to be acknowledged.
“But there is more to be done. Sadly, some police officers and staff are not confident being out in their police forces, particularly as they rise through the ranks, and some fear homophobia still exists in areas of policing.”
Stonewall chief Ruth Hunt told the Independent that LGB people would have more confidence in the police if they could “see themselves reflected in their local police forces.”
She added: “As demands on police forces increase, all staff and officers need to be able to perform to the best of their ability. Keeping secrets from your colleagues gets in the way of that performance.
“I’ll be calling on superintendents to make sure they create a culture where officers feel able to come out.”