Hollywood actor Danny Glover has slammed the death penalty as an imperfect form of justice that has sent many wrongly-convicted, innocent people to their deaths.

The LETHAL WEAPON star, one of a list of celebrities including Susan Sarandon, Tim Robbins and Alanis Morissette to appear in new London play The Exonerated, is a staunch opponent of capital punishment.

He says, "People believe in it because it taps directly into their fear. In that respect, it holds public opinion hostage.

"But it's not perfect and innocent people have died because of it."

The Exonerated deals with six people who were wrongly convicted and put on death row, including Sunny Jacobs, a woman accused of killing a police officer, who was freed after spending 26 years in jail.

Jacobs says, "The play has given us all a voice.

"Otherwise our experiences would take up 15 minutes on the news and then be forgotten.