Ander Poul was an undercover agent placed on the sandminer Storm Mine 4, along with D84, to investigate the threat of Taren Capel. When he went to look for Chub, he heard a scream and found Chub's body. He told the crew about the death of Chub.
Poul didn't think the Fourth Doctor and Leela murdered Chub. He released the Doctor and Leela and helped them investigate the murders. Poul eventually succumbed to Grimwade's Syndrome or "robophobia". He, Uvanov and Toos were the only surviving crew of the mine. (TV: The Robots of Death)