The Hampshire Constabulary officers were covertly recorded making “shameful” comments about suspects and colleagues.
They were heard comparing a black police officer to a mixed-breed dog, referring to women as “sugar tits” and “sluts”, saying Albanian nationals should be shot and that “illegal immigrants deserve the death penalty”.
The case comes after UK police leaders announced a “plan of action” to address racial inequality, following months of Black Lives Matter protests over the summer.
Six officers from Hampshire's Serious Organised Crime Unit (Socu) office in Basingstoke, Hampshire, were accused of breaching professional standards.
DS Oliver Lage, DS Gregory Willcox and PC James Oldfield have been dismissed, while retired DI Tim Ireson and former PC Craig Bannerman would have been sacked if they had not already left the force.
The sixth officer in the case, PC Andrew Ferguson, has been given a final written warning.
In October, the misconduct hearing was told that covert recording devices were placed in the unit’s offices between 9 March and 2 April 2018 following an anonymous complaint.
Jason Beer QC said the audio revealed behaviour “inconsistent with the values and standards of the police service in the 21st century”.
“This was a specialist police unit that enjoyed relative isolation from the rest of the force due to the sensitive and sometimes covert nature of the work that it undertook,” he added.
“That isolation and a lack of leadership by Mr Ireson and Detective Sergeant Willcox appears to have led to a toxic, abhorrent culture developing in the unit amongst some officers.”
Proceedings heard details of the actions and comments caught on tape, including frequent sexist and sexual references to women.
Mr Beer said: “It was a unit that was racist – a black officer is described as a ‘pavement special’, ie a mixed-breed dog.
“People are described as ‘pikeys’; a black officer is accused of behaving like a colonial overseer running a plantation of white people. When speaking to a black officer, a colleague puts on a fake Caribbean accent – in fact he was from Ghana; a detail like that doesn't matter; he was a black man after all.
“A black officer is accused of being flown to England from Africa in a crate and taken to London Zoo; all the time a song is sung in the background to the tune of ‘Buffalo Soldier’.”
He added that “offensive” photos of black men were shared on a WhatsApp group, which referred to the only black officer in the unit.
Officers were also recorded using derogatory terms for disabled, gay and transgender people and the recordings included inappropriate language towards suspects, calling them “f***ing c***s”.
Officers suggested that Albanian nationals “should be shot or even killed with a nerve agent” and that “illegal immigrants deserve the death penalty”, Mr Beer said.
He added: “It was a unit that was plain nasty, that displayed attitudes towards groups and communities that police officers are called upon to protect.”
Mr Oldfield was also accused of attending work after excessive alcohol consumption, and Mr Willcox was alleged to have falsely recorded hours of overtime.
In a statement, Hampshire Constabulary admitted that the discriminatory comments recorded had been neither “challenged nor reported” at the time.
The chief constable of Hampshire, Olivia Pinkney, said the language heard by the independent panel had “shocked us all and understandably left people with many questions about how this has been allowed to happen”.
“The public have a right to expect the highest standards from the officers and staff who are entrusted to keep them safe,” she added.
“These officers have failed to deliver on the promise they made to uphold fundamental human rights and accord equal respect to all people: the oath they declared when they took the office of constable.
“Policing has never before been under so much appropriate scrutiny to ensure an inclusive environment for all our officers and staff to flourish and bring their best.
“There is no place in my force, or in policing more widely, for those who do not live up to this standard.”
Ms Pinkney accused the officers of undermining public confidence in the police and damaging the reputations of colleagues.
She added: “I would hope that the public have seen that we don’t accept this type of behaviour, that when it is raised that we will take action and we will be open and transparent about that, no matter how difficult that may be.”
The Hampshire Police Federation, which represents rank-and-file officers, said the “outdated and offensive views” expressed had no place in policing.
The federation’s chair, Zoe Wakefield, added: “We are supporting all colleagues who were affected by this inappropriate and prejudiced behaviour and commend those who highlighted it.”
Additional reporting by PA