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Prosecutors say a former Rotorua CIB chief made "a sacrificial lamb" of one police officer to take the heat off Clint Rickards, Brad Shipton and Bob Schollum in the wake of Louise Nicholas' complaint of sexual offending by the men.
It is claimed John Buchanan Dewar - who said he knew the men on a professional basis only - was friendly with all three and had even been involved in group sex with Shipton and a women who will give evidence during the trial.
Crown prosecutor Mark Zarifeh told a High Court jury at Hamilton today, that Dewar had taken over the investigation into two separate complaints alleging sexual assaults, made by Ms Nicholas in 1993.
She claimed to have been sexually assaulted by a police officer in Murupara in the early 1980s, then again in the mid 80s at Rotorua by Rickards, Shipton and Schollum.
That attack was alleged to have involved use of a police baton.
Mr Zarifeh says Dewar "actively sought" to prevent a prosecution of the three men, by placating Ms Nicholas with an expedited prosecution on the first matter.
The officer in that case was finally acquitted after three trials, and has permanent name suppression.
Dewar is defending four charges of perverting the course of justice. It is alleged that on "on diverse dates" between January 14, 1993 and July 13, 1993 he suppressed, or failed to act on the allegations made by Ms Nicholas.
It is alleged he never took formal statements from Ms Nicholas in relation to the allegations against Rickards, Shipton and Schollum, then convinced her to concentrate on the first accusation against the other officer.
He faces further charges of twice wilfully giving false evidence in the case of the first officer, causing a mistrial each time.
At the first trial, he told the court of a conversation he had had with a witness, who was a family friend of Ms Nicholas.
At the subsequent re-trial, he gave unprompted evidence of an investigation he was running in relation to allegations made by Ms Nicholas concerning four police officers.
He faces a fourth charge of attempting to defeat the course of justice charge for his alleged "manipulation" of Ms Nicholas during a police investigation into his evidence at the two trials.
That offending is alleged to have taken place between May and July, 1995.
Mr Zarifeh said Dewar had covered for the Rickards, Shipton and Schollum as they had something over him in the form of the group sex allegations.
Dewar's lawyer, Paul Mabey, QC, in a brief opening statement denied outright the group sex claims.
More than 20 witnesses, including Ms Nicholas, will be called during the trial, which is set down for three weeks.
