Earlier this week (beg03Dec12), the two actors' co-star Harold Ramis was quoted as saying Murray was back onboard for the much-anticipated sequel - but it has emerged the comment was a hoax.
And now Aykroyd insists the movie will be going ahead without the man who portrayed Dr. Peter Venkman in the past two Ghostbusters films.
The Blues Brothers star tells Esquire magazine shooting will start at the end of 2013.
He says, ""Had Billy chosen to do the Eisenberg/Stupnitsky (screenwriters) script of two years ago, it would be out this summer, and it would be a massive hit. If Billy had said yes, it would have satisfied his performance and what he wanted in the movie, it would have satisfied his performing skill and how he wanted to be depicted in the movie, it would have satisfied the studio, the writers who wrote it, everybody.
""Then when he said, 'Absolutely not, I'm not in this,' we had to go and really rethink things. He abrogated his say in the project, abrogated his rights to have any say in it by refusing the third offer from the picture company, which his lawyer put before him, and Billy said, 'No, I can't respond.' Now we have to move on.""
But Aykroyd insists that doesn't mean Murray won't be welcomed back if he ever chooses to reprise his Venkman character: ""We'll always leave a hole for him. He's always there. He can always come back at any time and be rebuilt into it, as far as I'm concerned.""