Bill Nighy and Chris Geere are the latest stars to join the cast of 'Detective Pikachu'.

Ryan Reynolds is already on board to star in the first live-action Pokemon franchise movie, along with 'Inception's Ken Watanabe, 'The Get Down's Justice Smith and 'Big Little Lies' star Kathryn Newton.

Now Deadline has reported that 'Love Actually' star Bill and 'You're The Worst' actor Chris have also joined the cast.

'Detective Pikachu' is set to follow Smith's teenage character Tim Goodman, who has to team up with the mouse-like Pikachu in order to find his father who has been kidnapped.

Newton is set to star as a journalist.

In the movie based on the gaming franchise, Pikachu isn't as agile as the normal fan favourite Pokemon, so has to rely on his intelligence to beat his enemies, and he gets help from Tim - who is the only boy who can understand what the he says - to solve Pokemon-related crimes.

'Goosebumps' director Rob Letterman is set to helm the new movie and has teamed up with Legendary Entertainment to oversee the upcoming movie which has been written by 'Guardians of the Galaxy's Nicole Perlman and Alex Hirsch who has worked on 'Gravity Falls', according to Variety.

Rather than a standalone film it is expected that 'Detective Pikachu' will act as a launch pad for a new franchise.

The Pokemon Company's long-standing movie collaborator, Toho, will handle distribution of the film franchise in Japan, as it recently worked in partnership with Legendary on the reboot for the 'Godzilla' franchise.