Mason Pendrous last used his swipe card to get into his university accommodation on August 12.
For the next fortnight, it appears that nobody had seen the 19-year-old leave his room but his online activity "increased substantially" until his last contact with a fellow gamer on August 24.
The University of Canterbury commerce student's body would be found nearly a month later.
It has raised questions about how a young student could go unnoticed and be holed up in his room without any red flags being raised.
Experts have warned that excessive computer use or time spent online gaming can often be hiding bigger issues.
"If a person is choosing to disengage from society, family, and friends and exchanging that time with online activities, then that could signify a wider problem in that person's life," says NetSafe chief executive Martin Cocker.
"The time online is, more often than not, the symptom and not the cause."
England-born Pendrous was found dead by a staff member in his room, number 209 in the Hinoki building of the University of Canterbury's Sonoda Campus in Ilam, Christchurch, about 10.50pm on September 23.
His body had lay unnoticed for two to four weeks, a coroner ruled today.
After a special hearing in Christchurch to verify Pendrous' date of death, Coroner Sue Johnson found that he died between August 26 and September 10.
Uni student death: Body unnoticed 2-4 weeks - coroner
Stepfather's grief for student who lay dead in university accommodation
Stepdad of university student unhappy over death investigation
No cause of death has yet been established and police inquiries are ongoing, along with independent investigations by the University of Canterbury and accommodation provider, Campus Living Villages (CLV).
Stepfather Anthony Holland, who last spoke to Pendrous on July 19, has expressed concerns over how long it took to notice something was wrong, and that investigations into his death would paint his son as a recluse.
Today, Constable Robert Stokes, an inquest officer for New Zealand Police, revealed the police work done so far to try to establish when the teenager died.
Photo records have Pendrous last seen entering his accommodation block, and using his university swipe card, on the evening of August 12.
He was not seen coming or going for a fortnight.
The last time he's known to have spoken to anybody was on August 24 when he played an online war game with an old school mate in Wellington where they chatted over headphones.
From July 1 to the last time anyone saw Pendrous alive, police say his computer use had "increased substantially".
His high level of computer use remained consistent until 5.36pm on August 26 when the last clear record of user activity on his computer is documented.
The university's IT department established that Pendrous' laptop may have automatically logged on to the UC's Learn network after a software update at 5.41pm on the same day.
The last recorded text message was sent to his step-dad Holland on June 12, police found, while the last known verbal phone contact was also to Holland, on July 19.
His last bank transaction was at a nearby supermarket ATM on June 21.
Pendrous' cellphone remained logged on to the university's wireless service until it ran out of battery on July 23 and it was disconnected by his network provider on August 23 due to overdue payments.
A post mortem conducted by a forensic pathologist on September 24 concluded that he had been dead at least two to four weeks.
And today, after hearing the police evidence, Coroner Johnson agreed.
She ruled that Pendrous died between August 26 and September 10, 2019. The evidence, as it currently stands, suggests that he died in his room.
No family members were present at the hearing but a 3pm embargo allowed them to be informed of the outcome before media could report the findings.
While Coroner Johnson said she must focus on where he died, and the cause and circumstances of his death, it was important to remember that at the centre of it all was a well-loved young man just starting his adult life.
"His death was a tragedy and that mustn't be forgotten as we try to find some answers," the coroner said, and vowed that the young student would not become invisible during the coronial process.
• 'I disappeared from Sonoda and nobody noticed'