In a letter, detailed by the Financial Times, the SFO acknowledged the fact that it "inadvertently miscast" information when obtaining the search warrants and overlooked documents that contradicted the evidence against him.
The brothers have now launched a claim for £100 million in damages against the SFO for "wrongful arrest".
Robert Tchenguiz said in a statement: "My business, my family, and I personally continue to suffer losses as a result of the SFO's unlawful, aggressive and disproportionate action.
"The SFO's conduct has left me with no option but to take legal recourse in order to recover from the extensive financial and reputational damage they have caused, whilst also infringing my civil liberties."