A baby boy allegedly bitten, bruised and shaken was injured during a two-day drink and drugs binge, a court has heard.
Police made the disclosure as the child's mother, who faces child cruelty charges, appeared before magistrates in Belfast for breaching bail conditions.
The 19-year-old, who cannot be named to protect the infant's identity, was returned to custody for flouting an alcohol ban.
She was charged by detectives who have separately accused her former partner of causing grievous bodily harm with intent to the child.
The boy was aged around six months when he sustained the injuries in north Belfast in September 2009.
Both of the suspects are due to stand trial for the alleged offences in the new year.
During a previous court hearing it emerged that the child suffered up to 20 bruises to his body.
These included apparent adult bite marks and finger-tip bruising, according to the prosecution.
It was also contended that the baby had been shaken and may have suffered a blow to his head.
His mother had been released on bail to stay at a hostel outside Belfast.
Her barrister told the city's Magistrates Court that this was due to the notoriety of the case making other addresses unsuitable.
Paul Bacon said his client accepted breaching bail by taking two Bacardi drinks but argued that she could be released again.
“She is no danger to anyone else. The injured party in this case is her young son who has now been taken into foster care,” he said.
“Ultimately, this child will be adopted.”
But an investigating detective opposed bail due to the perceived risk of further offending.
He said the accused had “gone AWOL” in the past and informed social services she was going to visit friends who have children.
The officer also disclosed: “These injuries, we believe, were caused during a drinking and drugs binge over a couple of days.”
District Judge Fiona Bagnall expressed concern that the breach had occurred so soon after the accused was released from custody.
She refused to re-admit her to bail, directing instead that the case should be considered by a Crown Court judge who had allowed her out.