Sharmila Ullah was taken into police custody in July 2014 after being arrested for shoplifting.
The 30-year-old, of Fourth Avenue, was admitted to Walsall Manor Hospital from Bloxwich Police Station after suffering abdominal pain and vomiting.
The mother, known as Millie, was returned to her cell the following morning where a doctor certified her as fit to be detained.
But shortly after 11.50am on July 10 she was found unresponsive and pronounced dead at hospital less than an hour later.
It has now emerged a detention officer had made simultaneous entries on the police system stating he had visited Ms Ullah and other suspects being held in the cells when he had not.
The officer had instead checked on the detainees via CCTV.
The officer has since been dismissed by West Midlands Police for gross misconduct.
The force has also vowed to ensure steps are being taken to prevent misreporting in the future.
The findings come as the Independent Police Complaints Commission, which investigated the case, identified police failings and has now published its full report on the death.
IPCC Commissioner Derrick Campbell said: "Our thoughts are with Ms Ullah's family at this sad time for them.
"We carried out a thorough investigation as is right when someone dies in such circumstances.
"We have taken the family through our findings and hope they can take some comfort from the fact that the force has taken measures to address the issues identified."
Last year Ms Ullah's family declared they were 'disappointed' following the outcome of an inquest which concluded police failings did not contribute to her death.
In delivering his verdict Senior Coroner Zafar Siddique said her sudden death was down to long-standing alcohol misuse and alcohol withdrawal.
Ms Ullah's arrhythmia and liver damage were also taken into consideration as possible factors.
Following the hearing Sharmila's mother Beanto Ullah said: "She very sadly lost her life while in police custody in July 2014. The IPCC conducted a thorough investigation. They identified failings of the police relating to her detention.
"We are very disappointed the coroner did not similarly identify such failures when he set out his conclusions.
"We were particularly keen these matters were identified so the police could ensure all detainees in future are provided with the highest levels of care."
Chief Inspector Brian Carmichael, of the West Midlands Police Professional Standards Department, said: "West Midlands Police has accepted the findings of the independent IPCC investigation.We offer our sincere condolences to Ms Ullah's family."
The IPCC's full 55 page report on the case revealed the officer failed to visit Ms Ullah on three separate occasions.
He also did not conduct personal checks on ten other detainees that day as required.
"It is the opinion of the lead investigator that he has a case to answer for gross misconduct.