Three Met Police officers shared racist and deeply offensive messages and memes about black and disabled people in their WhatsApp group, a tribunal heard.
One such message allegedly compared Meghan Markle to a golliwog.
PC Sukhdev Jeer and PC Paul Hefford, along with former officer Richard Hammond, also failed to challenge and/or report the other members of the group after receiving the offensive messages, it is claimed.
The allegations amount to gross misconduct, which is so serious that the officers will be sacked if the allegations are proved.
Vishal Misra, for the Met Police, told the misconduct hearing in Fulham that PC Jeer contributed to the group the most, followed by PC Hefford and then former PC Hammond.
The trio were all part of a unit at Bethnal Green Police Station and were members of a WhatsApp group called 'But They Promised' that was active between January and December 2018.
Giving a 'flavour' of the kind of messages shared, Mr Misra said: 'All of the content in the log is submitted to be explicitly racist, homophobic, sexist, ableist and islamaphobic."
Mr Misra referred to another meme, one which showed the image of a ‘Golliwog’ toy that was captioned: ‘A sneak preview at Meghan’s wedding dress.’
Responding to this, PC Jeer said he did not find this funny even at the time.
‘The fact that someone is out there can create this, that is not a nice thing to do but I posted this on the group not to laugh at it but [to show] that there are people out there who still do this and find it funny.’
He added: 'All of the respondents failed to challenge one another with regards to the content being posted.'
The panel heard that PC Jeer posted an image of a young boy in a hoodie captioned as a 'monkey in the jungle' and superimposed with an image of a penis.
PC Hefford allegedly superimposed the same image with a disabled person.
Former PC Hammond is said to have sent a 'discriminatory message' about the London borough of Tower Hamlets.
'In explaining the message, former PC Hammond in effect said that people from the Bangladeshi community seem to accept election fraud as part of their democratic processes,' Mr Misra said.
The lawyer added that six discriminatory videos were uploaded onto the group.
The first five were posted by PC Jeer and the sixth by PC Hefford, the panel heard.
Summarising one video, Mr Misra said: 'It takes a scene from the movie Jurassic Park and plays the Jurassic Park theme tune and to that theme tune a man with disabilities is seen walking out of a building with the assistance of his carer.'
Describing another: 'It pertains to a website called funnyordie.com which shows a white woman stating that if you want to get good exercise in effect they will arrange for a black man to chase her around so that she can get exercise.'
Of a third: 'It shows somebody who suffers from dwarfism jumping into a body of water with sound effects designed to mock.'
It is alleged that the behaviour was 'prolonged' as the group was active for a year.
'There has been a persistent and prolonged failure by all of the respondents to adhere to the relevant professional standards,' Mr Misra said.
'The communities that are lampooned by all of the respondents in the WhatsApp group form part of the communities that they police.'
All three officers deny that their behaviour amounts to gross misconduct.
The tribunal continues.