Corrections would not comment further.
The sister of Mr Guy's widow Kylie, Chanelle Bullock, wrote on the Lets do it for Scotty Tribute page on Facebook that today was "the day that we wish never would happen".
She said Macdonald had been released from Christchurch Prison.
Macdonald met the Parole Board on October 16 to ask for early release for the fourth time.
His first bid for freedom was at Manawatu Prison, the last three at Rolleston Prison, near Christchurch.
Last year, the board decided Macdonald still posed a risk to the public. He had previously been described by as having "a significant personality disturbance".
While finding he no longer posed a risk, the board's decision imposed strict conditions on Macdonald for the six months after his release - including GPS monitoring, banning him from the North Island and stating he could not possess, own or use firearms, ammunition or restricted weapons.
He was also forbidden from contacting co-offender Callum Boe, a former worker on the Guy family farm, and must stay home at night.
He has a job and somewhere to live and the board says he's supported by friends and family, as well as professionals.
The panel that met him said at the time Macdonald was now seeking advice from others, which he had previously found difficult.
"He has practiced letting things go rather than holding grudges and ruminating about perceived wrongs.
"Importantly, he has also begun to share his feelings of frustration or sadness with others in prison and with members of his family."
Scott Guy's parents Bryan and Jo previously told NZME News Service they did not plan on having anything to do with Macdonald after his release.
Bryan Guy said the parole decision was not unexpected.
His daughter Anna was married to Macdonald and the pair had four children together.
The children had some contact with their dad when he was in prison and that was likely to continue, he said.
"I would have been surprised if they had kept him in much longer. I guess it's a little bit of a difficult time leading up to this for the family.
"We always knew that the day was going to come and we have put it to the back of our minds to some extent."
After his arrest, Macdonald sent Bryan and Jo a note saying he looked forward to getting back together and laughing about the old times.
But Bryan Guy said he did not plan to have anything to do with Macdonald.
"There's no need for us to," he told NZME News Service.
Macdonald had been employed as a carpenter at a unnamed firm's construction yard, as part of the Release to Work programme.
When the Parole Board announced last month that he was eligible for release, it noted that he had "approved accommodation and employment and a sensible release plan".
His stringent release conditions included:
• Not to enter the North Island without prior written consent by his probation officer.
•Not to possess, own or use firearms, ammunition, or any other restricted weapon unless prior written approval by his probation officer.
•To attend for a psychological assessment and attend and complete any treatment/counselling recommended by the psychological assessment to the satisfaction of his probation officer and treatment provider.
•To attend any programmes/counselling directed by his probation officer to assist him in parenting responsibilities to the satisfaction of his probation officer.
• To reside at a withheld address and not to move from that or any other approved address without the prior written approval of a probation officer.
• Not to stay away overnight from his approved address without the prior written approval of a probation officer.
• To notify his probation officer prior to starting, terminating or changing your position or place of employment, including voluntary work.
• Not to have contact or otherwise associate with any victim of his offending, directly or indirectly, without the prior written consent of his probation officer.
• Not to communicate or associate with co offender, Callum Boe, unless prior written consent given by his probation officer.
• To submit to electronic monitoring in the form of Global Positioning System (GPS) technology as directed by a probation officer in order to monitor his compliance with any condition(s) relating to his whereabouts.
