Dozens of passersby came together to save the life of a New Zealand lawyer by lifting a two-tonne London cab off her.

Claire Miller was knocked down by the taxi and pinned beneath the vehicle while on a lunch break in the UK's financial district on Monday.

An office worker filmed from a bulding above as around 30 passersby stopped and combined to lift up the taxi.

Tiaan Trahms Bystanders lift a London cab off trapped New Zealand lawyer Claire Miller.

The accident took place in King William Street, near the Bank of England in central London.

Recovering afterwards, Miller said: "Words cannot begin to express my gratitude for what everybody did - Londoners are great!"

Her firm, Beale & Company, added that Miller wanted to thank everyone that helped her after the accident.

London's Evening Standard reported the woman's legs were covered in what appeared to be black bruises, but she was still conscious.

Laura Fares was near a London Underground station when she was told a woman had been hit by a black cab.

She said she ran over to find two paramedics unable to reach the woman underneath the car.

"The cab driver was just leaning on the car, waiting for more help and the paramedic said he wasn't emergency staff so needed to wait for more people," Fares said. "They had a blanket on her and a pillow under her head.

"She looked like she was in her late twenties and she was really blue and blinking. She was sort of semi-conscious, but I could tell she was still alive.

"I said, 'Aren't we going to move the car off her? She's still alive.'

"He looked underneath the car and said that her leg wasn't too badly injured and said we could try and lift it."

Fares, 37, began calling for bystanders to help the rescue operation.

Witnesses reported seeing workers running out of their office buildings to help after hearing the shout, "Help, help, we need men."

Fares said: "I started yelling at people in the street, running up to them, especially men. I was saying, 'You're a man, there's a lady under the car you've got to help push.'

"There was a group of Spanish tourists who I even managed to draft in to help. It was mostly men in suits – dropping their briefcases to run and help."

"We did it in about three minutes. I was directing, telling them to pull and hold and eventually we lifted the car off her."

Builder Michal Raczkowski told the Standard: "I walked out into the street and saw the lady lying under the cab. Only her head and the top of her shoulders were sticking out, the rest of her body was twisted under the taxi.

"I called my friends and we ran over to her. One of the guys kneeled down and was telling her jokes, trying to keep her comfortable and get her to relax.

"She wasn't making much noise. She seemed like she was in a lot of shock, but she was awake and talking.

"The rest of us got around the front of the taxi and took the bumper and wheels and lifted it up and pushed it towards the pavement."

Millerjoined Beale and Company in February 2010 from the Dispute Resolution Group at Shadbolt LLP.

According to a company website, Claire specialises in construction law and dispute resolution.

She has worked in London since 2005.

A spokesman for the London Ambulance service said they sent "numerous resources" including an ambulance crew and trauma team to.

"We treated a woman reported to be in her 40s for leg and pelvic injuries. She was taken as a priority to hospital."

Miller was released from hospital and is said to be recovering from her injuries.