"The investigation found evidence that both council members and employees apparently failed to comply with internal systems and controls designed to ensure that proper processes were followed in the approval of council projects and the expenditure of public money.
"However, these are failures of governance and procedure, and no evidence of the intention required to commit a criminal offence was found."
Ms Read said the SFO findings did not warrant a referral to any other agency for further inquiry.
Mr Brown yesterday called on Mr Carter to reveal what aspects of the council's affairs were being probed and why. He said the secrecy surrounding the investigation cast aspersion on all council staff and contractors, and the public were being kept in the dark on what exactly was being investigated.
Mr Brown said he was not spoken to by the SFO as part of its investigation, which he said was a waste of taxpayers' money. But Mr Carter said the inquiry was a good use of public money.