Family of Sheku Bayoh joined relatives of other people who have died in custody to march on Downing Street at the weekend.
Grieving relatives of the 31-year-old father-of-two took part in the United Families and Friends Campaign annual rally, as their fight for the truth about his death continued.
Members of the coalition include the families of Leon Patterson, who died in police custody in 1992, Roger Sylvester, who died after being restrained by police in 1999, and Rocky Bennett, who died in psychiatric custody in 1998.
Mr Bayoh’s family also handed in a petition to 10 Downing Street.
The London march on Saturday followed summit talks in Westminster earlier in the week, when Mr Bayoh’s sister, Kosna Bayoh, told MPs of the anguish his loved ones are going through as they seek answers about how he died.
She said: “His mother is going through such pain. She’s crying every day. Her only son is gone.”
She claimed her brother was treated like an animal and said: “People should not die like this.
“We’re fighting for justice for Sheku. We will not rest as a family until we get justice.”
Mr Bayoh, 31, died on May 3 after being detained by police on Hayfield Road in Kirkcaldy.
The incident happened just a few hundred yards from the home he shared with his partner and baby son.
Police Scotland said officers had been responding to calls about a man brandishing a knife in the street and that a female officer was seriously injured in a confrontation with Mr Bayoh.
His death has become one of Police Scotland’s most controversial cases since the single force’s inception.
It is being investigated by watchdog the Police Investigations and Review Commissioner (Pirc).
His case is also to feature in a documentary film being made about deaths in police custody or following police contact.
A trailer for 1500 and Counting by filmmaker Troy Aidoo and writer, poet, journalist and producer Siana Bangura is to be screened on Thursday.
A crowdfunding campaign for the film has been launched.