The family of an inmate who was stabbed to death at Wormwood Scrubs prison have said conditions in the prison were "absolutely shocking".
Khader Saleh, 25, was found with a number of knife injuries on Wednesday afternoon (January 31) and was pronounced dead at the scene.
Four inmates at the west London jail have been arrested on suspicion of murder.
The victim's brother, Said Yousef, said Saleh had told his family about problems with gangs and violence inside the prison.
Speaking to BBC Radio London, he said: "I was just in a shock position since the time I heard.
"I wouldn't believe it because someone was inside the jail and got murdered in this way, it was really shocking for me."
He added: "He said there's a lot of gangs inside and that guards are not doing anything about it. It's basically they let it go if fight happen."
He has called for his brother's killers to be brought to justice: "I'm talking on behalf of our family and saying they have to get the highest sentence in the prison for the horrible things they have done."
Saleh's family has asked for his body to be released by the coroner so he can be buried in accordance with Islamic tradition.
Community worker Duale Yousef, who is supporting the relatives, said: "The police told us the coroner will hold another 28 days - Islamic way it has to be allowed for Muslims to bury their deceased ones."
He said the community is in shock, adding: "It's sad because I think Khader has been neglected and wasted his life - and the killers, we don't know who they are.
"What we looking for today is for justice and that justice must be served for Khader."
Mr Saleh was married with a young son, added Mr Yousef: "Khader has left as well a son and this young boy has lost his father today, he is fatherless," he said.
"He will know one day who murdered his father. But the reality is we feel unjustice (sic) - the way Khader has been treated in prison was absolutely shocking.
"I have heard that he has been beaten before his death and nothing has been done."
Four men, one aged 20, two aged 21, and one aged 23, arrested in connection with Saleh's death remain in police custody.
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