In episode four our sources take you back inside Downing Street as police enter Number 10 with a party in full swing. Paul and Nathan examine why the Met Police were so reluctant to investigate the lockdown-busting events for so long, only to deliver a dramatically timed u-turn. A former Met chief superintendent explains how the probe should have been done, before one of our sources reveals shocking new claims of the efforts staff took to cover up evidence of partying inside Number 10.

Partygate: The Inside Story was presented by Paul Brand. It was written by Paul Brand and David Williams with additional production by Nathan Lee and archiving by Lewis Denison, Elisa Menendez and Will Tullis. Audio production and sound design was by Dawn Kelly and Emma Roberts. The series was produced and directed by David Williams. The executive producer was Matt Williams.