The Mongrel Mob member, who bashed policemen while on parole, is set to be released from prison a year early despite concerns about his propensity for violence.
A Parole Board panel yesterday released its decision to free him from prison next month.
Hawke's Bay Today uncovered an email sent to the Department of Corrections from a prison guard, who said he had known Gillies for 10 years at Auckland Prison and held grave fears for the public's safety.
"Please do not release John Gillies," the email said. "You look in his eyes and he has no soul ... in short he is evil and nasty. I have known this man for 10 years. He will hurt again. I hope it's not my family and not yours but some family will suffer due to his release. Keep John in prison and away from us, I beg you. He will hurt again."
Gillies has been in prison since he was jailed for seven years in 2005 for assaulting two policemen and possessing cocaine and methamphetamine.
His arrest came on May 29, 2004, after a 13km car chase involving speeds of about 145km/h between Hastings and Waipawa.
Police found 10.5g of cocaine, 1.3g of crystal methamphetamine and cash totaling $21,040 in his vehicle.
The Mongrel Mob member has 106 convictions, 34 of them for violence, including one for stabbing Gisborne policeman Nigel Hendrikse with a screwdriver in 1993.
In a statement released yesterday, the Parole Board said Gillies had been "well-behaved" recently and showed signs of maturity.
"He turns 40 years of age next month and appears to be focused upon now trying to reintegrate into the community and to have the support of his family," the board said.
Gillies had shown "increased insight into his problems dealing with anger and violence", and had an improved ability to deal with difficult incidents in prison, it said.
However, the board stated he was still assessed as a high risk offender with close links to the Mongrel Mob - some of his family are members - and had shown unwillingness to undergo a drug counselling programme in prison.
In the past he had also escaped from custody and committed serious and violent offences.
Gillies was originally set to be released from prison on May 17, 2012.
An array of special conditions were imposed on his early parole, including that he abstain from all drugs and alcohol and stay at an appointed address until November unless he is given permission to leave by his parole officer.
He was also required to undergo a psychological assessment and receive drug and alcohol counselling.
An appearance before the Parole Board in 2007 saw him ordered to do drug counselling before he could be considered for parole.
Gillies was one of four Mongrel Mob members awarded compensation and an apology from the Crown in 2000 after they said they were tortured and abused by guards at Hawkes Bay's Mangaroa Prison in 1991 and 1993.
The Crown Law Office, acting under an Official Information Act request, said the total amount paid did not exceed $325,000.
He was also the subject of controversy when it was revealed he had a large "Mongrel Mob Forever" tattoo removed from his face during 15 $300 laser sessions paid for by taxpayers.