Two children who have been missing since Christmas Eve have been found in Auckland, according to a police spokesperson.

Lily, 10, and Pearl, 8, were taken on December 24, a police spokesperson police says.

They were last seen at 11pm on Monday, at a service station in south Auckland. Police were earlier urgently seeking information on their whereabouts, saying they had grave concerns for their safety.

Their mother is due in Wellington District Court on Wednesday after being arrested in Wellington on Tuesday.

An officer in court said the children had been found in Auckland.

The mother posted a video on Facebook on Tuesday evening.

'I am here at Parliament in Wellington because it is my hope that I can see the Prime Minister Jacinda Ardern, or at least she will see me,” she says in the video.

'There is an extreme problem that I have and I have tried going to many levels but it is not working. So it's my humble petition that I get to see her.

'It involves my two children and I.

'I have driven all this way. It has taken me nearly 24 hours. And without going into too much more detail, please Prime Minister Jacinda Ardern we need you.”

The car linked to the missing children was parked at Te Papa on Wednesday morning. Photo: Bruce McKay/Stuff.

A car in which they had been travelling was sighted at about 9.40am on Tuesday, in Devon St, New Plymouth. It is a silver 1994 Toyota Camry, registration CLR45, says the police spokesperson.

The girls' mother was found alone and arrested in Wellington on Tuesday about 9.45pm.

She refused to say where the children were, says the police spokesperson.

Police searched vehicles parked in central Wellington after her arrest, without finding the children.

'The woman has been meeting people through Facebook in the time we have been looking for her and the children, and it is possible she has left Pearl and Lily with one of these people,” Detective Senior Sergeant Kevan Verry said earlier.

'We believe these contacts may have been misled or are unaware of the true circumstances in this case, or the serious concerns that are held for the children's welfare.”

The car linked to the trio was parked at Te Papa on Wednesday morning.

-Stuff.