Police are investigating an alleged attack on a prison guard by Southport killer Axel Rudakubana.
The triple murderer allegedly left a member of staff at HMP Belmarsh in London with severe injuries.
According to The Sun, Rudakubana, 18, threw scalding water over the worker on Thursday.
The officer was rushed to hospital after the pre-planned attack, while police were called to the high-security unit.
Rudakubana is reportedly on the same unit as Manchester Arena bomb plotter Hashem Abedi, 28.
He was moved from HMP Frankland in Durham to HMP Belmarsh in Thamesmead after throwing hot oil at officers and stabbing them with improvised blades.
An investigation is now underway into how Rudakubana got hold of boiling water to hurl over the guard.
A source said: “This is terrifying and shocking in equal measure and questions will be raised about this attack, especially coming so soon after the one by Abedi.
"One of those will be why Rudakubana had access to boiling or hot water, and how on earth he was able to carry this out.”
A spokesman for His Majesty's Prison Service said: "Police are investigating an attack on a prison officer at HMP Belmarsh yesterday.
"Violence in prison will not be tolerated and we will always push for the strongest possible punishment for attacks on our hardworking staff."
Rudakubana was jailed for life in January for killing Elsie Dot Stancombe, 7, Alice Aguiar, 9, and Bebe King, 6, at a Taylor Swift-themed dance class on July 29, 2024 in Southport, Merseyside.
He also assaulted eight other children, class instructor Leanne Lucas, and businessman John Hayes, who attempted to disarm him.
During his trial, Rudakubana admitted producing the deadly toxin ricin, possessing terrorist material and possessing a knife
A public inquiry into the Southport murders began in April.
In February, Attorney General Lord Hermer rejected calls for the Court of Appeal to review the length of Rudakubana's sentence.
His minimum term of 52 years means he cannot be considered for release until he has served that amount of time in jail.
