Melissa Rivers, daughter of comedian Joan Rivers, has hired a New York law firm to investigate the circumstances behind her mother's death.

In a statement the firm confirmed that it was tasked by the family to "fully determine the facts and circumstances surrounding the death of Joan Rivers".

However they declined to comment further or say if Melissa Rivers intended to file a lawsuit against the hospital.

Rivers died earlier in September following complications during an examination on her throat and vocal cords. She was 81.

The New York State Health Department has launched an investigation into the clinic where Rivers was treated.