Kelsey Grammer, star of Cheers and Frasier, today reveals the personal heartbreak he still feels following the brutal murder of his sister Karen in 1975.

In a moving interview with BBC Radio 4’s Desert Island Discs, Grammer says that he honours his sister’s memory by ensuring her killer remains behind bars.

Grammer, 62, said: ‘I have learnt to forgive. I have even told the guy I forgive him, although I don’t advocate his freedom. I don’t think that is reasonable.’

Scroll down for video

Kelsey Grammer said he still feels the personal heartbreak following the murder of his sister

18-year-old Karen Grammer, left, was murdered and raped in 1975 by Freddie Glenn, right

Kelsey and his sister Karen are seen together in this 1974 photo - the year before she was murdered

The star, who has twice helped to block attempts by killer Freddie Glenn to get parole, said it was important to speak up for the rights of victim’s families.

He said: ‘In a letter to the parole board, I said the punishment shouldn’t be worse for the family than it is for the guy that killed the person and that’s what this feels like sometimes.’

Grammer, who was 20 at the time, said the murder had almost pushed him over the edge and his belief in God was shattered, but he has since recovered his faith.

Kelsey is seen with his wife Kayte Walsh at the 2017 Vanity Fair Oscar Party in February in Beverly Hills, California

Glenn was convicted in 1976 of killing Karen Grammer, 18, and two other victims chosen at random the year before.

Glenn and accomplice Michael Corbett snatched Miss Grammer on July 1, 1975, while she was outside the Red Lobster restaurant, waiting for her boyfriend to finish work.

The thieves had tried and failed to rob the restaurant and reportedly thought that the 18-year-old, who was sitting in her car, could identify them.

She was repeatedly raped over four hours at an apartment, according to KKTV.

She was then told she would be let go and released from a car at a mobile home park.

Kelsey and wife Kayte Walsh are seen on March 11, 2015 in New York City with their children Faith and Gabriel

Glenn, seen above in mugshots, was convicted in 1976 of killing Karen Grammer, 18, and two other victims chosen at random the year before

Glenn, who according to the trial had taken LSD, then slit the teenager's throat and left her on the ground to die.

She managed to make it to a nearby home for help but no one was home and she died on the back porch.

Her body was identified a week later by Kelsey.

Glenn was convicted of killing Miss Grammer and given the death penalty. he was 18 at the time of the murder.

The Supreme Court later overturned that decision and allowed him to seek parole after 30 years.

Karen Grammer, pictured, was repeatedly raped over four hours at an apartment

And at a parole hearing in 2009, Kelsey wrote a letter to the court saying: 'She was my best friend and the best person I knew. She had so much to live for. I loved my sister, Karen. I miss her. I miss her in my bones.

'I was her big brother. I was supposed to protect her - I could not. I have never gotten over it... It very nearly destroyed me.'

Glenn also murdered motel cook Daniel Van Lone, 28, in a robbery from which he took 50 cents on June 19, 1975.

On June 27 that year, he killed 19-year-old Army soldier Winfred Proffitt over drugs.

Glenn is locked up at Colorado’s Buena Vista Correctional Facility.

He received the death penalty but it was overturned on appeal.

Kelsey has suffered a barrage of heartache. His father was also murdered in a separate incident and his two half-brothers both died in a scuba diving accident, with their mother suspecting shark involvement.

Kelsey, who was born on the Virgin Islands, was only two years old when his parents, Allen and Sally, divorced. His father remained in St. Thomas, while Kelsey was taken by his mother to New Jersey.

Eleven years later Allen was shot and killed by intruders at his home. His sister's murder came a further seven years later.