Jane Fonda saw Rob Reiner and Michele Singer Reiner just one day before they were killed

She wrote on Instagram on Monday (15.12.25): "I saw them night before last looking healthy and happy.

"I am reeling with grief. Stunned."

In an emotional tribute, Jane described the couple as "smart, funny, generous people", and revealed she had been working with them on launching the Committee of the First Amendment, which was originally established by Jane and other Hollywood stars in 1947.

The organisation was relaunched in October in an attempt to battle censorship in entertainment and media.

She continued: "Rob and Michele Reiner were wonderful, caring, smart, funny, generous people, always coming up with ideas for how to make the world better, kinder.

"They had been helping me launch the Committee for the First Amendment."

Rob and Michele had attended a Christmas party hosted by Conan O'Brien the night before they died.

According to PEOPLE magazine the couple were seen having a heated argument with their son Nick Reiner at the bash.

The married couple were found dead at their home the next afternoon, and Nick has since been arrested and charged with murder.

He is being held without bail.

Last month, Jane spoke about her "tough year" after already losing friends Gene Hackman, Robert Redford and Diane Keaton in February, September and October respectively.

Speaking to People at the Georgia Campaign for Adolescent Power's EmPower Party, Jane said: "It's been a tough year."

She added of Hackman: "You know, there's him and Redford.

"He came down her to support GCAPP. And we screened Barefoot in the Park."

The Barbarella star continued: "And Diane Keaton - I just finished working with her. Boy, I was shocked. Really shocked. You get to be old and everybody is dying around you."