Until recently, it is understood that his only visitors were members of An Garda Síochána, preparing him ahead of giving evidence against Hutch
The father-of-four was sentenced to four years in prison last October after he pleaded guilty to facilitating the murder of David Byrne at the Regency Hotel in 2016.
He gave evidence for the State against his former friend Gerry ‘The Monk’ Hutch, and gave explosive evidence over a fortnight at Hutch’s murder trial in December.
The former Sinn Féin councillor has been in Limerick prison since November 2. Until recently, it is understood that his only visitors were members of An Garda Síochána, preparing him ahead of giving evidence against Hutch.
But in recent weeks it is understood the 44-year-old has received at least two visits from a female family member.
This woman, who is not involved in criminality, was escorted by an armed garda for her own protection.
The Irish Prison Service (IPS) was contacted but a spokesman said it could not comment on individual prisoners.
As one of the most high-profile inmates within the prison system, Dowdall poses a significant security concern for prison authorities as well as gardaí.
As 25pc remission is applied to all prison sentences handed down in the State, he will serve just three years behind bars.
His father, Patrick Dowdall (65), was jailed for two years for his role in facilitating the murder of Kinahan cartel associate Byrne.
The father and son are under a 23-hour-lockdown regime in a special protection wing of the prison, where they are housed in cells beside each other.
Both men, especially Jonathan, are under the “severest threat level possible” because of his decision to give evidence against Hutch.
As part of the protective regime surrounding the north Dublin pair, they are not allowed to mix with other prisoners.
All their meals are delivered to their individual prison cells and they can only take their hour of exercise time when other prisoners are on their meal breaks.
For the hour they are out of their cells they are closely monitored by prison staff.
Limerick Prison was chosen as the facility to house them because the jail does not have any known criminals involved in the Hutch-Kinahan feud that has claimed 18 lives.
Dowdall’s trial previously heard he was being considered for the witness protection programme and that following his sentence he would likely need to relocate to another country for his own safety.