It is unclear who is returning to the new movie, which will continue the story of Caesar, the evolved ape who is brought to life via motion capture by Andy Serkis.

Plot details are being kept secret, but Harrelson will play a character called the Colonel.

It was recently reported that Gabriel Chavarria would play one of the new characters, but insiders say his part is small.

Harrelson is currently shooting LBJ, starring as President Lyndon B. Johnson, and will be back on the big screen in the final Hunger Games movie, which hits theaters on Nov. 20.

The actor is undergoing a resurgence thanks to the critical acclaim for his work on the first season of HBO’s True Detective.

Harrelson is repped by CAA and Ziffren Brittenham.