One policemen's desperate and moving account of how he tried for decades to bring a paedophile priest to justice - but was blocked by not only the Catholic church, but by his own Police Force.

One policeman's desperate and moving account of his decades-long struggle to bring a depraved paedophile priest to justice - only to find himself obstructed by the Catholic Church and betrayed by his own police force.

Monsignor John Day died in 1978. He was arguably Australia's most prolific paedophile. His victims are counted in the hundreds. Yet when Day died, he was feted by Bishop Ronald Mulkearns as having 'faithfully fulfilled his ministry in God's name'.

The Church had been well aware of Day's activities. For years his crimes had been overlooked and tacitly endorsed. Unbelievably, Day had committed his terrible crimes with the knowledge and protection of senior members of the Victoria Police as well as the Clerk of the Courts, the most senior officer of the court in Mildura in the 1960s and '70s. Together the three men cast a shadow over the city that remains today.

Denis Ryan, a young police detective from Melbourne, had transferred to Mildura in the early 1960s. By the tacit rules of the day, priests were not to be charged for any crime short of murder in Victoria. The influence of the Church both in the Victoria Police and within the office of public prosecutions was too strong. But Ryan was a good cop, and quickly gained the trust of the people of Mildura. One by one the victims started coming forward-children who had been molested by Monsignor Day and their shocked and sometimes disbelieving parents.

Armed with a dozen or more signed statements, Ryan had sufficient evidence to lay charges. Then began his nightmare, as his every step towards bringing Day to justice was blocked by the Catholic Church and then the Victoria Police. Ryan struggled for decades to have his story and those of Day's countless victims heard, but shamefully, this will be the first time this tragic tale is made public.

This is Ryan's story, told in his own words. It is also the story of Day's victims, many of whom are alive today, and are here for the first time given a voice.

After all this time, at last the truth can now be told.