Eyewitness: Woman drove into Christchurch lake, man dived in after her

Police divers have been called in to searching for two people missing after a car went into a lake in southwest Christchurch.

Witness Jordan Fleming was walking his dog past the Westlake Reserve this evening when he saw a woman in a red hatchback in the car park, and a man outside who was trying to open the driver's door.

"I heard the accelerator go and that's when the car went off the bank down the hill into the lake," he said.

The man jumped in and swam after the sinking car, diving and resurfacing several times, Fleming said. Then he dived and did not reappear.

Police were called at 5.45pm to reports that a vehicle was submerged in the lake in the suburb of Halswell.

Police and rescuers at the scene, searching for two people believed missing after a car went into the lake. Photo / Broadcast Media

"There are staff there working to determine if anybody was in the car," a spokeswoman said.

Firefighters attended the incident but have now left the scene. Ambulance officers are still at the lake.

A police spokeswoman told the Herald it was still unclear if anyone was in the vehicle, despite police and fire officers diving in and attempting to see inside.

A car has been found submerged in the lake at Westlake Reserve in Christchurch. Photo / Google

"Extra police staff are on their way to the scene to speak to witnesses to ascertain what has occurred," police said.

"A scene guard will be in place overnight and no further information is available at this stage."

Fairfax reported it was suspected two people were inside, but the vehicle had not been found because the lake was so deep.

A police spokesman told Fairfax that "numerous people went into the lake with ropes to try and get to the vehicle".

The police dive squad will arrive in Christchurch on Wednesday to join the search, police said in a statement.

Police staff and other emergency services had been in the area and in the lake tonight, working to establish what happened and speaking to witnesses.

A scene guard will be in place overnight.

The lake sits in the middle of a housing development in Halswell. Residents say it's a deep former shingle quarry popular with runners, walkers, cyclists and children feeding ducks.

A car-park is cordoned off and guarded by police.

The lake is now in darkness. Torch lights appear on the far side as locals scan the shoreline.

It's located just 200m from Checketts Ave where Helen Milner, dubbed the Black Widow, murdered her husband Phil Nisbet in 2009.

Checketts Ave is also where builder Michael McGrath lived before his mysterious disappearance in May.

Police searched the lake during their massive, and so far unsuccessful, hunt.

"With the Black Widow and Michael McGrath and now this, it's pretty weird and sad for the families," one local resident said.

Earlier a large crowd of around 50 people stood at the shoreline.

Witnesses say two people who tried to save the pair who went into the lake have been taken away by ambulance.

Various bystanders say eyewitnesses have told of hearing a car's engine revving before accelerating into the lake.

A diver went into the lake earlier but came up indicating he could not reach the vehicle, locals say.