A 17-year-old man is in custody charged with manslaughter and has interim name suppression.
He is yet to enter a plea and the case will be transferred to the High Court at Auckland later in the month.
Belgrade news site Kurir quoted a close friend of Milosavljevic saying his death marked a string of tragedies for the family, following the death of his parents shortly before Christmas.
His family reportedly drove him to the airport and were returning when they crashed on the outskirts of Belgrade, at Bubanj Potok. Kurir reported that after landing in New Zealand Milosavljevic returned to Serbia on the first available flight for the funeral.
The friend was reportedly "greatly shaken" by Milosavljevic's death.
Kurir also reported Milosavljevic tried desperately to start a new life in New Zealand for at least a decade so he could support his family, but it's unclear when he first arrived in the country.
He had worked for Countdown Papakura for eight months and had also spent a short time working at the Takanini branch.
A former colleague said Milosavljevic was always speaking fondly of his children.
"He did everything for them. They were the reason why he went to work," Countdown Takanini supervisor Kahu Rangi-Dixon said.
"He was a lovely kind man, just extremely lovely. He put himself out there to make sure (staff) were okay and we were safe."
If customers were problematic he tried to talk and reason with them first and if they showed signs of aggression he would back down immediately, she said.
"That's why I don't understand why anyone would do this."
Serbian community elder Nebojsa Joveljic didn't know Milosavljevic but recognised him through his work, and described his death as a tragedy that had shaken people.
The Serbian community was so small in Auckland Jovelji was surprised Milosavljevic hadn't reached out to the sole church, the Serbian Orthodox Mission Parish of King St Milutin, in Point Chevalier.
"This is a real tragedy for the whole Serbian community and we're all very concerned that this is happening in a peaceful country like New Zealand," he said.
"I've had a few people contact me, Serbian people who are living here. We have families in Papakura and we are all deeply distressed because of this event. We didn't have a chance to meet him and know more about him, especially because of his tragic personal things which happened, which is quite an unusual story."
It's understood the church was supporting the sons, and a funeral was understood to be being prepared for Tuesday.
A Countdown staffer told Newstalk ZB host Marcus Lush that the site had been blessed by a kaumātua amid an outpouring of sympathies from the local community.
Manurewa-Papakura Ward councillor Daniel Newman is acting spokesperson for the family and said it was an "extremely traumatic" time, and they had requested privacy.
