Robert Charles Best, 70, pleaded guilty in the Melbourne County Court on Monday to six offences between 1975 and 1988 which involved three victims.

Best's pleas ended a long legal pursuit for justice by victims, investigators and prosecutors.

His pleas also lift a court ban issued almost a year ago that enables The Standard to report that juries in six separate trials since November have found Best guilty of 21 sex offences against eight victims.

He was acquitted of two charges of sexual penetration and gave evidence in some trials, which were held consecutively and all tenaciously defended.

A complainant died before one trial.

Best's admission of guilt also ended the need for a further five trials.

Charges were found proven by juries, or Best entered guilty pleas, in relation to 11 of 15 complainants.

Police collected statements from complainants between 2002 and 2008.

There was a committal hearing in 2009 and the 11 trials started in November last year.

Best was principal at Ballarat's St Alypius Catholic Primary School between 1969 and 1973.

He taught at the Christian Brothers' College (now part of Emmanuel College) in Warrnambool between 1989 and 1994.

Before his time in Warrnambool, Best had taught in Fremantle and Launceston during the 1960s, East Ballarat 1968-73, St Leo's in Box Hill 1975-85 and St Joseph's College in Geelong from 1985-89.

In July 1996 Best received a nine-month suspended sentence for the sexual abuse of an 11-year-old pupil in 1969.

During 1998 he won a retrial after being jailed on similar charges for two years. The retrial did not go ahead.

Christian Brothers Oceania issued a statement after Best's guilty plea, offering a "sincere and unreserved" apology to the former students sexually abused by him.

Its executive officer for professional standards, Brother Brian Brandon, said the Christian Brothers were "deeply saddened by these events, especially the great distress and suffering caused to these victims and their families".

He added that the Christian Brothers ''view abuse in any form and, particularly, the sexual abuse of the young and the vulnerable as repulsive''.

Best's pleas to six charges, including two of aggravated indecent assault of a boy under 16 will result in the discontinuation of some charges and a permanent stay of others.

Prosecutor Amanda Forrester said Best's pleas "will clear all of the matters in respect of this accused crimes committed between 1969 and 1988".

Defence counsel Sarah Leighfield asked that a date for a plea hearing be set in July to allow reports on Best from an oncologist and a psychologist.

Best, who told court on Monday he was a retired teacher now of Port Phillip Prison, will return to court on July 25.

The south-west has previously been labelled the paedophilia capital of Australia due to the number of former priests and Christian brothers who have been found guilty of sex offences in the region.

In 2006 Paul David Ryan, 64, was sentenced in the Warrnambool Magistrates Court to a minimum 12 months' jail for abusing two boys at Penshurst in 1990.

Gerald Ridsdale, Bryan Desmond Coffey and former Catholic brother Edward Dowlan, who each served in the Warrnambool area, have all been found guilty of sex charges.

In 1994 Ridsdale was sentenced in Warrnambool to 18 years in jail, which was effectively extended by another four years after he was found guilty of another 35 offences in 2006.

athomson@standard.fairfax.com.au