The inspectors found that Mr John Furze conspired with a suspected drug smuggler to prevent a Florida house being seized, writes Joe Humphreys.
The Cayman banker Mr John Furze conspired with a suspected drugs smuggler to prevent "by fraudulent means" the US authorities seizing a property believed to have been obtained as the proceeds of crime, the report found.
In a section entitled "The Pruna affair", the inspectors detailed Mr Furze's involvement with the Pruna family, some of whom were being investigated in the US for drug-related offences.
Those under investigation included Mr Andreas Pruna, and his brother Fernando, a former political prisoner in Cuba who in 1993 was sentenced to 12 years' jail in the US for drug trafficking and attempting to bribe a witness.
Mr Furze arranged loans for both individuals at a time when the US Drug Enforcement Administration was trying to prosecute them and seize their assets.
The report said: "Mr Furze's involvement in the affair of the Pruna loans is one of the most bizarre matters in the whole Ansbacher saga."
The Moriarty tribunal has already heard that loans of more than $3 million were made to Mr Fernando Pruna and his associates by Guinness & Mahon in Dublin with the backing of Cayman Island deposits.
The inspectors confirmed this link, giving specific details of a loan which appeared to have been made to Mr Andreas Pruna and his wife, Maria Isobel, and which was secured on a property at Miami Beach, Florida.
In November 1985 Mr Pruna wrote to Guinness & Mahon saying he would be unable to make the first interest payments and he had doubts about his ability to repay the principal sum. He offered to transfer the deeds of the property to the Dublin bank in lieu of foreclosure.
By further letter on Guinness & Mahon notepaper, the bank appeared to accept the offer, and to arrange for the property to be registered in the name of Mars Nominees, its nominee company. This registration took place but later steps were taken to convey the property by warranty deed to Ms Maria Isobel Pruna.
In their report the inspectors said no bank documentation relating to the "alleged loan" existed.
They said that Guinness & Mahon had informed them that "the loan was a fiction", and that Guinness Mahon Caymen Trust (GMCT) had falsely used the Dublin bank's notepaper to create the alleged correspondence between it and Mr Pruna.
In 1988 Mr Furze wrote to Mr Des Traynor to inform him that the Prunas were under investigation in the US. He explained that they were clients of Cayman and that Mars Nominees would be involved in the investigation because the Miami Beach property had been registered in its name.
Mr Furze alleged in his letter that he had not known this. But the inspectors said they believed "on the balance of probabilities, Mr Furze not only knew of the registration of the property in the name of Mars Nominees, but also was active in bringing it about."
They said: "It is not possible to say whether anyone in Guinness & Mahon was complicit in the affair, but it is clear that Mr Furze could easily have obtained Guinness & Mahon headed notepaper on his trips to Dublin, without the involvement of any other person.
"The inspectors are of the view that there is thus evidence tending to show that Mr Furze, acting in his capacity as a director of GMCT, conspired with Mr Andreas Pruna in an attempt to prevent, by fraudulent means, the forfeiture of the Miami Beach property by the US authorities."
The report also details Ansbacher's dealings with Mr Jesus Barrios, an associate of the Prunas who had been indicted of charges, including operating a cocaine and marijuana smuggling operation in the US between 1981 and 1988.