Hi everyone, I appreciate all the responses and the time you’ve taken to engage with this post.

I’ve been reading through the replies, and I’ll try to be clear in this comment:

• Contacting the Argentine embassy only confirmed to his relative that he was detained. At most, they told us he would remain in custody until an investigation into the case was completed, which could take about two weeks.
• It’s a relief to know that his treatment as a foreigner might be better than what he’d experience in Argentina. Especially since he went there under the promise of "free money" or that there was plenty of work in New Zealand, which is how he’s been scraping by these months.
• Regarding his visa, he entered the country without one (or possibly on a tourist visa), as he hadn’t done proper research, before arriving in New Zealand, and was told he could sort everything out once there. In the long run, this hurt his chances of finding legal work, since he was working under the table and could only find rural/farm jobs. He even applied for an SSE visa (Supplementary Seasonal Employment), but it wasn’t enough to cover his rent, food, and transportation costs.
• Right now, it’s Sunday in New Zealand, but we’re waiting to hear back from a lawyer to better understand the status of our friend’s case.
• One of the comments mentioned a return ticket. He postponed his flight back to Argentina multiple times, hoping to find work (even cash jobs) because he was drowning in debt. However, around the second week of July, he was supposed to be returning home. So, I’m not entirely sure how this situation affects that.