It has completed its investigation into Hanover Finance Ltd - the last of the 2007/2008 finance company collapse to be investigated.

The investigation took the SFO 32 months.

Acting chief executive Simon McArley said it was the most extensive of the investigations, with 107,000 pages of evidence, 3730gb of data and 120 hours of interviews.

The SFO had concerns about Hanover’s solvency at the time dividends were paid during the six months before payments were suspended in July 2008, about the financial condition of the companies disclosed to investors compared to its actual position, some transactions made immediately before payments were suspended that did not benefit the company but substantially benefitted some related parties, and the accuracy of the companies’ assets in financial statements that were sent to investors as part of the 2008 debt repayment proposal.

But for charges to stick, the SFO would have to prove that the people in charge of the companies knew of the circumstances and caused them with dishonest intent.

“Recent decisions relating to other failed finance companies have highlighted how difficult it is to satisfy this standard,” McArley said.

“SFO’s prosecution decisions must also be made within the context of the Solicitor-General’s prosecution guidelines. These require me to be satisfied that there is a reasonable prospect, based on credible and admissible evidence, that an impartial jury could be satisfied, beyond reasonable doubt, that the person prosecuted has committed a criminal offence. On the basis of the evidence currently available, SFO is not able to reach that threshold. As a result it is unable to commence any criminal charges in relation to Hanover Finance and its related companies.”

He said that if new evidence surfaced that illustrated knowledge and intent of those in control of the company, the SFO might reconsider.

“While many may view the conduct that occurred at Hanover Finance as egregious, that alone is not sufficient for me to commence a prosecution,” he said.

“This is a case that has attracted huge public attention and is of significant public interest.  I believe that this justifies the vast time and resources that SFO has dedicated to it. However, we have now exhausted every available avenue of enquiry and the time has come to move on and focus our resources elsewhere.”