The Independent Office for Police Conduct (IOPC) announced on Wednesday that there is no need to formally investigate contact between Metropolitan Police officers and the 40-year-old.
Officers from the force last had contact with Flack on December 13, 2019, when she was in custody following an alleged assault on her boyfriend Lewis Burton.
It has been reported that in the aftermath of that incident, she told officers she would take her own life. She died two months later on February 15.
She was bailed after an initial court hearing and would have been due to appear for the start of her trial on Wednesday.
After her death, Flack’s management team criticised the CPS for conducting a "show trial", with Mr Burton having said he did not support a prosecution, and Flack having denied the charge against her.
Following a Freedom of Information request from the Daily Mirror, it is understood the CPS will look into its handling of the matter through a post-case review panel, a procedure which is not uncommon, especially in regard to complex or sensitive cases.
It is understood the outcome of the review will not be made public.
An IOPC spokesman said: "Having considered a mandatory referral from the Metropolitan Police (MPS), we decided the matter did not require investigation by the Independent Office for Police Conduct because there was no indication of a causal link - directly or indirectly - between the actions or omissions of the police and Caroline Flack's tragic death."
The Metropolitan Police said its internal standards department had found no further action is necessary over the case.
A spokesman said: "The DPS has concluded that a formal investigation is not required.
"A comprehensive review of the circumstances surrounding all police contact with Ms Flack following her arrest and detention has already taken place as part of the referral process.
"No conduct has been identified on the part of any officer. In line with normal processes, if any new information should come to light it will be considered and action taken as appropriate."
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She had written: "Within 24 hours my whole world and future was swept from under my feet and all the walls that I had taken so long to build around me, collapsed. I am suddenly on a different kind of stage and everyone is watching it happen.
"I have always taken responsibility for what happened that night. Even on the night. But the truth is .... It was an accident."