Mr Suta, a self-confessed long-time supporter of Kelly, has extensively researched the bushranger’s history and his trial.

The trial has been described by Mr Suta as a sham, with Kelly failing to get a fair hearing.

The letters were apparently written by Benalla bank manager George McCracken, who comments on apparent police cowardice and the unwanted advances of a constable towards Kelly’s sister, Kate.

They have been handed over to Mr Suta by a person who was given the letters in 1980 by a descendant of Mr McCracken.

“The letters are not earth-shattering, but they are significant,” Mr Suta said.

Mr McCracken wrote to his mother in early 1879 on Colonial Bank of Australasia letterhead.

The confrontation between Kelly, his gang members and police happened at Stringy-bark Creek near Mansfield in October 1878.

Three policemen were killed and two months later there was a bank hold-up at Euroa by Kelly and his associates.

The first letter by Mr McCracken was on January 3, 1879, and he said there was “great dissatisfaction at the movements of the police in the matter of the Kellys”.

“People are beginning to declare against the force in general and after the gang are caught a thorough investigation into the force’s conduct and work ... will take place,” he told his mother.

Mr McCracken repeated newspaper reports that the outlawed Kelly, along with brother Dan Kelly, Joe Byrne and Steve Hart, were at the New Year’s Day races at Benalla.

Police apparently knew they were there, but Mr McCracken said no one could understand why action was not taken against the gang.

Kelly sympathisers were arrested in the first week of January and remanded in Beechworth jail without any evidence against them being given to a magistrate.

Mr McCracken made reference to an incident at the Kelly homestead in April 1878 where a constable apparently tried to force himself on Kate Kelly, then 14.

The constable was wounded, either by Ned or his own hand, and it led to a vendetta against the Kellys.

“If what Ned Kelly says is true with regard to the treatment his sister received, it is no wonder that he and his brother had such a hatred against the police,” Mr McCracken wrote.

He said nothing could justify them murdering police officers in cold blood.

But public sympathy “seems to lean a little towards them and I doubt whether any of the numerous friends would betray them”.

Mr Suta said the content of the letters supported Kelly, his followers and family.

He said Mr McCracken was a protestant and unlikely to back Ned, a Catholic, unless there was some justification and truth in allegations against police.

Mr Suta said the letters had been gifted to Ned’s great grandniece, Joanne Griffiths, who is working to establish a trust for artefacts and memorabilia associated with the Kelly family.

It is hoped the letters can be displayed at a Kelly exhibition opening at the Bendigo Art Gallery on March 28.