Bill Murray found 'Ghostbusters: Afterlife' physically demanding.

The 71-year-old actor reprises his role as Dr. Peter Venkman in the latest movie in the supernatural comedy franchise and admits that it was hard stepping into the role of the ghost-catcher once again.

Bill – who is joined in the movie by fellow original 'Ghostbusters' stars Ernie Hudson and Dan Aykroyd – told the I newspaper: "I ended up doing the same stuff as the first one!

"And I'm looking at Ernie and Danny going, 'This hurts!' You're on the ground again with those damn (back) packs on, getting knocked down. Did we really do this all the time? It was physically hard."

The original 'Ghostbusters' film was released in 1984 and proved to be a critical and commercial hit and Bill recalled how movies bosses were desperate to make a sequel that would ultimately follow five years later.

The 'Groundhog Day' star said: "So much of the momentum was about making the money. I went five years before we made the second one. Five years! And they were pushing for it the hour after the first came out."

Bill also made an appearance in the panned all-female 'Ghostbusters' in 2016 – which starred Melissa McCarthy, Kristen Wiig, Kate McKinnon and Leslie Jones – and has no regrets about featuring in the project.

He said: "I did that because I like those girls. I don't mean to sound important, but that was a case of saying, 'Okay, these girls are funny. They deserve a shot to make this thing and why shouldn't girls get to be Ghostbusters?'"