Michael Keaton claims the new Robocop costume is a "sissy suit."

The actor - who appears in the cyborg cop reboot as Raymond Sellers, CEO of the evil Omnicorp organization - joked the special effects armor Joel Kinnaman had to wear as the title character wasn't a patch on the rubber suit he had to don to play Batman in 1989.

"That sissy suit - they have air conditioning in it. [When I played Batman] I couldn't do [any] of that because I couldn't get up to go the bathroom. They put me in this thing and inside, honestly, I started having panic attacks. Literally, panic attacks. So, I thought, 'I don't know how I'm going to do this, man. I'm feeling really, really scared.'"

While costume design has come on since the 80s, Joel said his 45lb suit was still difficult to wield, and took almost two hours to put on each day. "It was a bit of a challenge to put on. It was so uncomfortable, it was digging in everywhere, it was pressing down on my shoulders, and I was sweating like a pig. After twenty minutes, I said, 'I gotta get out of this!' And then, it was a daunting idea that I was going to have to wear this for 14 hours a day, six days a week for five months," he said.

Having been through a similar process, Michael, 62, could relate, but didn't offer much sympathy. "I enjoyed every minute of watching. I'd just sit there in my little business suit and watch him. There was a lot of gloating," he added.