A “defenceless” two-year-old boy was murdered by his mother and her boyfriend after suffering a “catalogue of very significant” injuries in the weeks before he died, a court heard.

Kyrell Matthews died with 41 rib fractures, as well as significant internal bleeding and bruising, allegedly caused by “very forceful squeezing or blows”, prosecutors say.

Kyrell’s mother, Phylesia Shirley, and her then-boyfriend, Kemar Brown, deny murdering the boy at Shirley’s home in Thornton Heath, south London, on October 20 2019.

Opening the case at the Old Bailey on Tuesday afternoon, prosecutor Edward Brown QC told jurors: “What you will hear in the evidence amounts to no less than a determined pattern of repeated and significant assaults, on a completely defenceless and young child.

“And it will be no surprise to you that the effect of these injuries would have been real pain, not only on their infliction, of course, but also pain and discomfort after and following each violent episode.”

Your Local Guardian: ourt artist sketch by Elizabeth Cook of Phylesia Shirley, and her partner, Kemar Brown, appearing at the Old Bailey in London charged with murder and causing or allowing the death of a child, Shirley's two-year-old son Kyrell Matthews who died after he was found in cardiac arrest at a home in Thornton Heath, south London, on October 20 2019ourt artist sketch by Elizabeth Cook of Phylesia Shirley, and her partner, Kemar Brown, appearing at the Old Bailey in London charged with murder and causing or allowing the death of a child, Shirley's two-year-old son Kyrell Matthews who died after he was found in cardiac arrest at a home in Thornton Heath, south London, on October 20 2019

He added: “It is the prosecution case that the injuries were inflicted on that very young child by the defendants Phylesia Shirley or Kemar Brown or both of them.”

Shirley and Brown had been in a relationship for approximately a year when Kyrell died, a month after his second birthday.

Jurors heard Kyrell did not attend a nursery and so was in the full-time care of his mother, then aged 21.

Brown, however, spent almost all of his time at Shirley’s one-bedroom flat and regularly slept over, jurors were told.

Neither defendant was employed in the period leading up to Kyrell’s death, the court heard.

Prosecutor Mr Brown said: “They therefore together had constant and consistent care of the child.

“You immediately understand the relevance of that issue.”

Shirley, 24, and Brown, 28, of separate addresses in Thornton Heath, deny murder.

Brown also denies two further charges – causing or allowing death, and causing or allowing serious physical harm to a child.

Shirley has admitted allowing the death and allowing serious physical harm to a child.

The prosecution opening will continue on Wednesday, along with a short response from the defendants’ barristers.