The theft took place in a lift at the Exchange shopping centre in Ilford shortly before midday on Wednesday 26 July.
The victim, a 69-year-old pensioner, had withdrawn £1,000 cash from a branch of Lloyds Bank before getting into a lift to return to her daughter's car in the car park.
When she got into the lift, two of the suspects pressed a different floor button and discussed the buttons pressed with the victim as the third suspect searched her handbag and removed the cash.
When the victim returned to the car she realised her savings, which were in her purse, had been stolen.
The first suspect is a white woman in her 40s with long dyed white hair.
She was wearing a black leather jacket over a black and white chequered top, bleached blue jeans with holes in the knees and black shoes.
The second is an Eastern European man in his 30s with short black hair. He was wearing a green jacket, blue jeans and blue trainers with white laces.
The third suspect is an Eastern European man in is his 40s with receding short dark hair. He was wearing a grey suit jacket over a black top, blue jeans and blue trainers with white soles.
He also had black rimmed glasses on his head.
PC Carl Repper, from the East Area Command, said: "We are appealing for any information as to the identity of these three suspects.
"The victim has lost a large amount of her savings as a result of her ordeal."