Beard said a 21-year-old and an 18-year-old were arrested in relation to the kidnapping. Both women would appear in the Auckland District Court tomorrow facing kidnapping and burglary charges.
He said a large team of police officers had been making inquiries all day.
"The baby's parents are obviously very distraught and have been through a terrible ordeal and they are currently with their baby," he said.
"This has been an extremely harrowing time for the new parents of a very young baby. We are relieved and thankful that the baby was not harmed and has been reunited with her parents."
Police were still working to establish the circumstances around the kidnapping.
Beard said police were not looking for anyone else in relation to the kidnapping.
Police were unable to release further details because the matter was before the courts, he said.
Epsom MP David Seymour said the parents called him this morning after their baby had been taken to make sure everything possible was being done to find their daughter.
"It's unbelievable," he said. "They were just distraught.
"It is difficult to imagine a more harrowing thing that could happen to parents, especially of a newborn baby."
Seymour said he believed the baby was taken from the family house but would not reveal details of how it had happened.
"Clearly they have been targeted by some one pretty sick," he said.
Seymour said he had been working with them on another issue prior to the baby's birth and the couple were excited about the arrival of their first child.
"[Having a baby] is probably the most exciting thing that can happen to two people and to have that taken away ..."
The parents had been back in touch to let him know their daughter was safe and had already joked it would make a great 21st story.
Seymour said every part of New Zealand had to deal with crime.
"It's always been a reality that bad things can happen in nice neighbourhoods ... You can't predict when something completely diabolical like this will happen."
He said about 80 police officers were tasked with finding the baby this morning and praised police for getting the girl back to her family so quickly.
Earlier, nearby resident Dane Bonnici said about six police cars and three or four unmarked ones were parked outside the house in Pah Rd, near Selwyn Rd, about 7.30am this morning.
There was police tape across the driveway and around the fence, he said.
About five marked police cars and two unmarked ones were still at the house when Bonnici drove past again about 1.30pm.
He said police officers were standing on the footpath outside the property and appeared to be guarding the house.
Bonnici also saw police in blue boiler suits on the property this afternoon.
It was usually a quiet area and to have so many police at one house was surprising, he said.
"I presume it's something fairly serious if they've got cops there all day," he said.
A man from a neighbouring unit, who asked not to be named, believed the family had moved into the house two to three months ago.
At least 10 police cars had descended on the property this morning, including forensics teams and unmarked cars.
He initially thought there had been a robbery but they told him it was more serious than that. He said he felt "kind of safe" since moving in two years ago, although there had been a burglary at one of the units in the past few months.
Police were "evasive" about the case, and had told locals not to speak to the media, according to another neighbour.
He said the area was "so safe", despite the incident.
"It's the loveliest place."
Staff at the nearby Elizabeth Retirement Home said they had received calls from neighbours asking what was going but they had not heard anything either.
A staff member said the house was taped off and police cars were parked outside the house when they arrived at work in the morning but no one knew what was happening.