Authorities are investigating a claim that a female prisoner became pregnant after an affair with a male inmate.
Margaret Henderson, who is on remand at Hydebank Wood on the outskirts of Belfast, has claimed she is pregnant and that the father is a prisoner serving in the facility's Young Offenders Centre.
Henderson (29) is accused of murdering Greenisland pensioner Eddie Girvan, who was found dead at his home at Station Road in January.
His hands had been tied behind his back and he had a stab wound to the chest.
It is understood that Henderson recently confided in a member of staff that she believed she was in the early stages of pregnancy, and that she had been involved in a brief affair with an inmate from the Young Offenders Centre.
The Belfast Telegraph understands that Henderson is refusing to undergo medical tests to substantiate her claim.
If she is pregnant, a paternity test will have to be carried out to determine if the male prisoner is the father.
It is understood that Henderson was temporarily released from Hydebank Wood in recent weeks.
The Northern Ireland Prison Service confirmed that an investigation was under way.
A spokesman said: "While the Prison Service does not comment on individual prisoners, we are aware of this allegation.
"This is being investigated and until we are able to establish the full facts it would be inappropriate to comment further."
If the pregnancy is confirmed it will raise embarrassing questions for the Prison Service and the bosses at Hydebank Wood, at which the women's prison and Young Offenders Centre are separate.
Alastair Ross, the former chairman of Stormont's justice committee, described the development as highly concerning, but urged caution.
"While at this point these remain unsubstantiated claims, the fact that it is a possibility highlights why the current provision for female prisoners remains inappropriate," the DUP MLA said.
"It is important that the facts are established, and if these claims are proven to be true, then a full investigation needs to be carried out.
Henderson was living in a Belfast hostel when she was arrested and charged in January with Mr Girvan's murder.
During her first court appearance her lawyer described her as "an extremely vulnerable and fragile woman".
Two men, aged 23 and 24, who were also arrested in connection with the murder were later released unconditionally.
Mr Girvan's body was discovered by police officers after they called at his house during a routine enquiry.
When they arrived the doors were locked.
After gaining entry they found the 67-year-old dead on a chair, with his hands tied and with a knife wound to the chest.
Detectives later suggested they were investigating if the murder was linked to online dating sites.