There has been a second security threat at Parliament today.
Police were currently at the incident, at the rear of the building.
The incident comes as Parliament debates this year's Budget in the House.
The area behind Parliament has been cordoned off and access was blocked.
Earlier, Parliament was in lockdown after a security alert on the forecourt.
Police said they've arrested a man for driving onto Parliament grounds.
They have cleared the vehicle and it will be removed from the forecourt as soon as possible.
MPs have been told to stay away from windows of the Beehive.
A spokeswoman for Finance Minister Bill English said the incident wouldn't delay the Budget announcements at 2pm.
A central Fire Service spokesman said they attended the incident to assist police.
They left the scene about 12.30pm.
He would not comment on the incident further as police were lead agency dealing with the incident.
A police spokesman said several specialist teams were involved in the police's response to the incident, including the police dog team.
A video of the scene shows the vehicle smoking and people fleeing.
Security officials can be seen telling civilians to move away from the area while a policeman examines the vehicle with a police sniffer dog.
United Future leader Peter Dunne says he can see a car in the forecourt, which has been cleared.
Labour MP Jacinda Ardern has tweeted an image of the vehicle, saying: "This has shown up on the forecourt of parliament and it looks like the person driving it was just arrested"
A police spokeswoman said they are still working to establish the situation.
The vehicle is displaying a sign addressed to John Key. They have blocked off the front entrance to the Beehive.