Baby was kidnapped by woman posing as nurse.

Police in Italy reunited a one-day-old baby girl with her parents four hours after she was abducted from a maternity hospital in the southern city of Cosenza on Tuesday.

Italian prime minister Giorgia Meloni on Wednesday expressed her "heartfelt thanks" to the police officers for their "extraordinary" work in successfully tracking down baby Sofia.

The nightmare for the baby's parents began early on Tuesday evening when a man and a woman entered the maternity ward of the Sacro Cuore clinic, on the pretence of visiting a relative.

Fake nurse

On arriving at the room where the newborn was staying, the woman posed as a nurse and said she had to take the baby to be checked by doctors, Corriere della Sera reports.

She then took the infant from its unsuspecting grandmother's arms before fleeing the hospital with the man who was waiting for her in the hall with a pram.

After an extended period of time the baby's parents, growing concerned that she had not returned, raised the alarm.

Race against time

A major police operation immediately swung into action across Cosenza, with all exit routes in the city blocked, as officers sifted through hospital security camera footage in a race against time.

The investigation provided police with the faces of the kidnappers as well as the car they were driving, leading officers to the couple's home within a few hours.

When the police arrived at the apartment, they found the front door decorated with a blue ribbon, symbolising the birth of a boy.

Relatives unaware

Inside the house, festivities were underway to celebrate the baby's birth, with relatives at the party apparently completely unaware that the baby had been kidnapped.

The woman had allegedly faked a pregnancy for nine months and announced on social media that she had given birth to a boy, according to state broadcaster RAI News.

After locating baby Sofia, police commissioner Claudio Sole took the newborn in his arms, saying: "I was the first to pick her up and I never let go".

Police then arrested the couple, a 51-year-old woman from Cosenza and her 43-year-old husband of Senegalese origins.

Disbelief

"As soon as we entered we saw people in disbelief and even the woman's husband", Sole told reporters, adding that investigators would have to "evaluate" how the man could not have known the baby was not his daughter.

"I asked the woman where the baby was and she showed me a room where there was a cradle with the little girl who was dressed in blue" - Sole said - "It was all decorated for a boy. The woman then fell silent. When we took the baby, emotion replaced the tension we felt."

Police then returned little Sofia, in good health, to her young parents at the clinic in Cosenza.

Happy ending

"You are writing to me in thousands, from all over Italy", the baby's mother Valeria Chiappetta wrote in an emotional post on social media, accompanied by a photo of Sofia being kissed by her brother.

"This is our family that was crumbling into a thousand pieces last night. The police did an exceptional job, while I had lost hope", she said, paying tribute to "an entire city, or rather region" that came to a halt in an effort to find the missing baby.

 "I don't think I'll ever get over this, but the happy ending is that Sofia is fine. Thank you all. I would like to hug everyone", Valeria wrote, signing the post from "A mother and father who died and were reborn yesterday".