Police yesterday revealed that Liame Deane, who was serving a life sentence for the murder of his baby daughter, was found dead in his cell at the prison in Armley on Sunday.
Deane, 22, was jailed last month after he admitted to killing two-day-old baby Luna at the family home in Wakefield.
And today, a Prison Service spokesperson said an investigation into his death in the jail will now led by the Prison and Probation Ombudsman (PPO).
The PPO is an independent body that carries out investigations into deaths and complaints in custody.
The spokesperson said: “HMP Leeds prisoner Liam Deane died in custody on Sunday November 12.
"In addition to the police investigation, there will be an investigation by the independent Prisons and Probation Ombudsman.
"It would be inappropriate to comment further at this stage.”
Deane lost his temper during the night and subjected Luna to an attack when she continued to cry.
He admitted punching Luna to the face, squeezing her body and arms and shaking her.
Luna was taken to Leeds General Infirmary, where she died in intensive care on July 14.
The case was adjourned until Thursday when a hearing will take place at Leeds Crown Court.