The ITV series A Confession uses an all-star cast to dramatise Detective Superintendent Steve Fulcher's decision to breach police protocol in a desperate bid to catch Halliwell.
Sherlock star Martin Freeman plays Mr Fulcher, Joe Absolom plays Halliwell and Imelda Staunton plays Karen Edwards, mother of 20-year-old Becky Godden.
Becky disappeared in 2003 and this disappearance became linked to the search for missing 22-year-old Sian O'Callaghan in 2011.
Sian walked home after a night out to see her boyfriend Kevin Reape, played by This Country star Charlie Cooper in the drama, but never arrived there.
Mr Fulcher believed both girls were being kept alive by Halliwell and had the former taxi driver take him to to Barbury Castle, near to where he believed Sian was being kept, instead of taking him into custody and given access to a solicitor.
In the real-life investigation, Halliwell and Fulcher talked for four hours before the killer confessed and offered to show the detective where Sian’s body was.
They drove to the White Horse at Uffington where Halliwell admitted to killing Becky. Her remains were found in a field at Eastleach.
By not taking the suspect to custody and offering him access to a solicitor, Mr Fulcher broke the rules of the Police and Criminal Evidence Act.
Halliwell received a life sentence with a minimum of 25 years in 2012 after being convicted of Sian's murder. However, the charge of murdering Becky was dropped because of the rule breach..
It was four years before he was tried and eventually found guilty of the 2003 killing.
During the trial he admitted he made the confession because he knew the rules had been broken and he wanted to destroy the detective’s career.
The Independent Police Complaints Commission then found Mr Fulcher guilty of gross misconduct. He kept his job but resigned in 2014, later saying he suffered stress and had to take anti-depressants.
Becky’s mother was one of those who supported him, saying at the time: “He is and will always be my hero and I will always be eternally grateful."
The series, co-produced by ITV and Urban Myth Films, will air later this year and has been directed by Paul Andrew Williams, who worked on Broadchurch.