Former Durham officer Mohammed Perwaze, 46, was acquitted of 20 charges in October last year, including 18 relating to the alleged abuse of the same girl.
The collapse of the case was not reported at the time due to a reporting restriction.
Mr Perwaze, of Barnard Castle, Co. Durham, has always protested his innocence and says he is the victim of malicious allegations.
He went on trial last year at Sheffield Crown Court, but prosecutors later offered no evidence against him.
Judge Jeremy Richardson QC instructed him to be cleared of all charges, including ones alleging he was violent towards two young boys.
Immediately after he was acquitted, Mr Perwaze issued a statement thanking his legal team and said: “I was absolutely delighted that at last the CPS (Crown Prosecution Service) offered no evidence against me and that I was finally exonerated.”
On Monday, he told the Press Association: “I have always been completely innocent and the allegations made against me were intentionally malicious.
“I did state this to police during my initial police interview. I have lost so much as a result of this, the impact this has had and is continuing to have is devastating for me and my family.
“I will continue to seek justice and will not stop until those responsible are held to account for their crimes against me.”
In a statement, Durham Constabulary said: “An investigation was launched by Durham Constabulary in October into issues which arose during the trial.
“Five people – three women and two men – have been interviewed under caution in relation to offences of attempting to pervert the course of justice and fraud offences. Enquiries are ongoing.”
The force said that the allegations faced by Mr Perwaze were not related to his duties as a police officer.
A spokeswoman said he was dismissed by Durham Constabulary for gross misconduct on unrelated matters.