MPs on the Commons Select Committee on Health are to investigate the mistreatment of elderly people in care homes and by family members.

They want to try to gauge the true extent of abuse and whether "race and gender affect the incidence of abuse".

Expert bodies have evidence that sexual abuse of elderly people, including rape, is increasing. Action on Elder Abuse estimates that 500,000-800,000 pensioners a year are suffering abuse of some kind.

Gary Fitzgerald, chief executive of Action on Elder Abuse, said: "Of all the types of abuse that gets reported to our helpline, sexual abuse of older people is going up.

"We had a care assistant this year who was sent to prison for ripping the finger nails out of a woman in her 80s. We also had a 78-year-old who died within her family. She had cigarette burns down to the bone and cuts thought to have been from a razor blade."

Paul Burstow MP, Liberal Democrat health spokesman and a member of the committee, said that the problem was on a large scale and "going unnoticed and neglected".