A software designer told prosecutors in the Casey Anthony trial she searched for 'chloroform' once not 84 times, as they asserted.
As soon as John Bradley realised the mistake he alerted prosecution lawyers and the police, but had already testified against Anthony on June 8.
Mr Bradley claims the revised research was not presented to the jury and the record was never corrected
As the chief software developer of CacheBack - the programme used by police to verify the computer searches - Mr Bradley found 'chloroform' was searched once through Google.
That search led to sci-spot.com, also visited once, which gave information on the use of the chemical in the 1800s.
The 84 searches for chloroform was a lynch pin in the prosecution's case to suggest that Anthony had planned to murder her two-year-old daughter Caylee
Mr Bradley thought he was being called to testify about his CacheBack software.
But instead said he found himself being asked repeatedly about a Sherrif's Office report.
This report, written by police in August 2008, detailed Anthony's internet search history using NetAnalysis software.
Despite being a witness Mr Bradley said he was never told about the report by police or the prosecution.
'I had translated the data into something meaningful for the police,' Mr Bradley told the New York Times.
'Then I turned it over to them. The No. 1 principle for them is to validate the data, and they had the tools and resources to do it. They chose not to.'
Suspicious, and also concerned a woman's life was at risk - Anthony faced the death penalty if convicted - Mr Bradley redesigned his software to check the police data.
He found both reports inaccurate - although NetAnalysis had arrived at the correct result.
Both types of software had failed to fully decode the entire search file.
After going through everything again Mr Bradley found sci-spot.com was visited just once.
Mr Bradley said he immediately contacted prosecutor, Linda Drane Burdick, and Sgt Kevin Stenger of the Sheriff’s Office in late June via email and by phone to tell them of the mistake.
Sergeant Stenger said he was aware of the discrepancy, according to Mr Bradley.
'I gave the police everything they needed to present a new report,' Mr Bradley said.
'I did the work myself and copied out the entire database in a spreadsheet to make sure there was no issue of accessibility to the data.'
He even offered to fly to Orlando at his own expense to go through the findings.
Despite Anthony being cleared of murder, the revelations have angered her defence.
Defence lawyer Cheney Mason told the Times it was 'outrageous' that prosecutors withheld critical information on the 'chloroform' searches.
'The prosecution is absolutely obligated to bring forth to the court any and all evidence that could be exculpatory,' Mr Mason said.
'If in fact this is true, and the prosecution concealed this new information, it is more than shame on them. It is outrageous.'
'This was a major part of their case,' Mr Mason added.
Spokesman for the Orange County Sheriff's Office, Captain Angelo Nieves, hit back at the claims saying Mr Bradley had a vested interest in coming forward because his software was used.
'We’re not going to relive the trial again,' Captain Nieves said. 'We are not prepared to do that nor are we going to participate in that.'
The State Attorney’s Office in Orlando did not immediately return a call for comment.
Anthony was released from the Florida jail she has been in for the past three years last Sunday and hasn't been seen since.
However she may have fled to Carlsbad, California, according to the Today Show.
The private Pilatus PC-12 jet Anthony was whisked away on that morning is owned by California attorney Todd Macaluso's firm, according to the news programme.
Macaluso had, at one point, been a member of Anthony's defence team and had given her $70,000.
The firm has an office at the Palomar Airport in Carlsbad.
The plane 'enables us to travel anywhere within the United States in seven hours,' according to the company's website
