A nurse died Monday after 42 years in a coma following a brutal rape, in a case that led India to ease some restrictions on euthanasia.

Aruna Shanbaug suffered brain damage and had been in a vegetative state in a Mumbai hospital since being strangled with a dog chain and sexually assaulted by a hospital worker in 1973.

The 66-year-old Shanbaug had suffered a bout of pneumonia in recent days and was on a ventilator, officials at King Edward Hospital in Mumbai told the Press Trust of India news agency.

Shanbaug was attacked by a ward boy in the basement of the hospital where she was discovered 11 hours later, blind and suffering from a severe brain stem injury.

Left bedridden, she spent more than four decades being cared for by a team of doctors and nurses at the hospital.

Her attacker was freed after a seven-year jail sentence.

"Her actual death happened in 1973 (the date of the attack). Now what has happened is her legal death," her friend and journalist Pinki Virani told Zee News TV channel.

"Our Aruna has given our country a big thing in the form of a law on passive euthanasia," Virani said.

Shanbaug's plight became a focal point of debate on euthanasia in India after Virani appealed to India's top court in 1999 to allow her to die with dignity.

Indian laws do not permit euthanasia or self-starvation to the point of death.

But in 2011 the Supreme Court decided that life support could be legally removed for some terminally ill patients in a landmark ruling that allowed "passive euthanasia" for the first time.

The court said withdrawing life support could be allowed in exceptional circumstances, provided the request was from family and supervised by doctors and the courts.

The supervision was required to prevent "unscrupulous" family members attempting to kill off wealthy relatives, the Supreme Court had said.

The court however rejected Virani's request to stop Shanbaug being force-fed on the grounds that she was not legally eligible to make the demand on Shanbaug's behalf.