The incident happened on the night of 20th January 2016.
Northern Region Prison Spokesperson Austin Masangwale confirmed of the development in an interview with the press and identified the suspect as Muda Mhango.
Masangwale said Mhongo who is answering murder charges killed Abel Jere, aged 45, who was convicted of unlawful wounding in Mzimba.
Jere’s body is currently at Mzuzu Central Hospital for postmortem.
He said investigations are in progress to establish the cause of the incident.
Information at hand indicates that Mzuzu prison is currently accommodating 580 prisoners against the recommended number of 200 inmates.
The country’s prisons hold over 12 000 prisoners out of their expected holding capacity of 5 000.