The Ministry of Justice (MoJ) has launched an inquiry into mental health in prisons after 2016 recorded the highest number of prison suicides in England and Wales since records began.
Figures obtained by the Guardian via a Freedom of Information (FoI) request reveal that self-inflicted deaths rose to 113 last year, while cases of self harm rose by more than 25%.
It compares with 89 deaths in 2015 and the previous record high of 96 in 2004.
Dr Phillip Lee, a junior justice minister, has started an inquiry into prison suicides to see whether there is a pattern and whether policy changes are needed to the way mental health assessments are conducted in prisons.
Despite the move, prison reform campaigners have long argued the cause for self-harm and violence in prisons is caused by budget and staff cuts, as well as by severe overcrowding.
In November, the Howard League for Penal Reform published a report in which it documented at least 102 cases of prison suicide in 2016.
In the report, Howard League chief executive Frances Crook said: "The number of people dying by suicide in prison has reached epidemic proportions.
"No one should be so desperate while in the care of the state that they take their own life and yet, every three days a family is told that a loved one has died behind bars.
"Cutting staff and prison budgets while allowing the number of people behind bars to grow unchecked has created a toxic mix of violence, death and human misery."
Justice Secretary Liz Truss has said immediate action was being taken to improve security in prisons and that an additional 2,500 prison officers were being recruited to plug the gap.