A baby initially believed to have been abandoned outside a commercial complex earlier this week has "rapidly" recovered from the ordeal, police said Thursday.

The baby was rushed to hospital in stable condition late Tuesday morning, but the infant's condition deteriorated to critical, Toronto police Const. David Hopkinson told CBC Toronto.

Police initially believed that the baby had been born prematurely, Hopkinson said. That turned out not to be the case, he said, and the child's condition has greatly improved.

"The baby has rapidly made a recovery and is strong and healthy," Hopkinson said, noting that the infant is still being monitored by doctors.

The baby's mother, who also needed medical attention on Tuesday, is also doing well, he said.

While the entire incident is still under investigation, Hopkinson said, police are not expecting to lay charges. As such, he would not release further details about what happened Tuesday morning, when police were called to a plaza at Keele Street and Lawrence Avenue around 11 a.m. for a newborn found at the rear of the complex.

Police initially believed that the person who called 911 had found the baby a half hour before calling and taken the infant to a place of safety. When police found the baby it was in medical distress, Hopkinson said, so paramedics rushed the infant to hospital. The mother was found after a "short search," he said.

Hopkinson would not divulge more details citing privacy concerns, including whether police still believe the newborn was abandoned.