From the outset, one big question has haunted detectives looking into the death of young Welshman Gareth Williams. How could his body have ended up locked inside a relatively small bag in the bath at his apartment in Central London?! In this episode Dr Sian Williams hears from two people who have attempted to lock themselves inside a similar size holdall but with altogether different outcomes

Death of a Codebreaker is presented by Dr Sian Williams with contributions from Lewis Allsop, Wayne Wright and Dyfan Rees.
Producers: Wayne Wright and James Pepper.
The Executive Producer is Ashley Byrne.
Research by Wayne Wright, Ashley Byrne and James Pepper.
Music by Robin Forrest
The Sound editor is Mark Burrows
Death of a Codebreaker is an MIM Production for BBC Sounds and BBC Radio Wales.