Scientist Stephen Hawking has backed the right for people who are terminally ill to choose assisted suicide to end their lives as long as proper safeguards are put into place to ensure the action is voluntary.

Hawking, who at age 21 was diagnosed with motor neuron disease and told he had two to three years to live, is speaking about one week before the release of a new documentary based on his life.

Hawking, who is wheelchair-bound, has since become one of the world's leading scientists, known for his international bestseller A Brief History of Time. The now 71-year-old is using his own experiences to back up his arguments for assisted suicides, which according to Fox News, are illegal in his native Britain.

"I think those who have a terminal illness and are in great pain should have the right to choose to end their own life and those that help them should be free from prosecution," he said.

Hawking then referred to his own personal experience from 1985, when he was placed on a life support machine during a bout with pneumonia, and his first wife, Jane Hawking, was given the option of having the machine turned off, which she refused, insisting he be returned to Cambridge from Geneva. Hawking later recovered, and this experience is the one that serves as his cornerstone for why it should be okay if certain precautions are in place.

"There must be safeguards that the person concerned genuinely wants to end their life and they are not being pressured into it or have it done without their knowledge and consent as would have been the case with me," he said.

According to The Telegraph, the Department of Public Prosecutions issued in 2010 that guidance would protect friends and family members for prosecution for assisting a loved one's suicide, though it is still a criminal offense to encourage or assist someone in taking their own life.

This and other topics are ones Hawking speaks about in Hawking, the new documentary.

Hawking will be released in Britain on September 20.