Dessa röster är inte avsedda att vara kvinnliga. De är avsedda att vara tvetydigt gendered och därmed alien-sounding.
"I met Elizabeth who I love and I think I will shoot with her something for sure," Besson told AAP in Sydney.
The French director seemed impressed by Debicki's versatility as she took on the role of a male alien - the emperor of a compassionate alien race known as Pearls - in his epic space adventure set in the 28th Century.
"We pitched her voice just a little bit so you don't even know if it's a man or a woman. He (the character) is an emperor in fact, but she's a wonderful actress."