Hopes for an end to the protest at Maghaberry Prison in Co Antrim were raised when one of the four inmates climbed down off the roof.
Prison visits to all parts of the jail will resume today, including Bush House, where two of the protesters remain on the roof, and at Roe House, where a third prisoner is continuing his protest.
A spokeswoman for the Northern Ireland Prison Service confirmed that one of the prisoners had ended his protest at about 6.45am.
The protest began on Thursday afternoon as a Government-appointed review team visited the jail as part of its inquiry into staff and inmates' concerns.
Tensions have been running high at the prison in recent months, with demands for segregation by dissident republicans and loyalists.
A number of republicans are currently engaged in a "dirty protest" as part of their call to be placed in a separate wing from loyalist prisoners.
So far the prison authorities have resisted their calls.
At one stage during the current rooftop protest the prisoner unfurled a banner reading Segregation Now.
In June, a similar protest involving eight prisoners took place at Roe House.
The homes of several prison officers have been attacked with pipe bombs in recent weeks and army bomb experts have been called to deal with hoax devices at the prison.
