Justice Minister Kiri Allan is facing charges following a crash overnight.

In a statement released this morning, Prime Minister Chris Hipkins confirmed Allan is facing charges of careless use of a motor vehicle and refusing to accompany a police officer.

She was also issued an infringement notice for having excess breath alcohol between 250 and 400mcg.

A police spokesperon says they received a report of a crash involving two vehicles on Evans Bay Parade in Roseneath, Wellington, shortly after 9pm.

"One person was taken in to custody and is assisting police with inquiries into the circumstances of the crash.

"The road was blocked for a short time, no injuries are reported."

Hipkins says Allan was taken into police custody and held at Wellington Central Police Station.

She was released around 1am.

Hipkins says she also returned a breath test over the legal limit but at a level considered an infringement offence. Police have not pressed charges in relation to that.

"While her alleged actions are inexcusable, I’ve been advised she was experiencing extreme emotional distress at the time of the incident," says Hipkins.

"Her recent personal struggles with mental health have been well documented and it appears some of those issues came to a head yesterday. 

"I have spoken with her first thing this morning and advised her I do not believe she’s in a fit state to hold a Ministerial warrant. 

"I believe it’s also untenable for a Justice Minister to be charged with criminal offending. 

"Kiri agrees, and she’s advised me she wishes to resign all her portfolios immediately, is heading home, and taking time to consider her future in politics. I’ve accepted that resignation."

In a statement to media, Allan says she will "immediately resign all my portfolios".

"I’m heading home and will be taking time to consider my future in politics," says Allan.

"Over recent weeks I’ve faced a number of personal difficulties. I took time off to address those, and believed I was okay to juggle those challenges with the pressure of being a Minister.

"My actions yesterday show I wasn’t okay, and I’ve let myself and my colleagues down.

"I accept that my position as a Minister is untenable.

"I’m very sorry for my actions, the harm they could have caused and the embarrassment it has placed on the Government and my colleagues."

Hipkins says he recently provided Kiri the opportunity to address her mental health issues.

"After taking some time out I believed she was okay and was assured by her she was.

"Last night’s incident is evidence there are not always quick fixes when it comes to mental health, and the best thing for Kiri right now is to focus on her whanau and her wellbeing away from Parliament.

"I don’t provide this detail to diminish her actions, they were indefensible, but to provide context for the distressed circumstances she found herself in when the incident occurred.

"I will confirm the reallocation of her portfolios later today."