The body of a University of Canterbury student lay unnoticed in campus accommodation for 2-4 weeks, a coroner has ruled.

Mason Drake Pendrous, a 19-year-old commerce student, died between August 26 and September 10 this year, Coroner Sue Johnson found after a special hearing in Christchurch today to verify when he died.

No cause of death has yet been established and investigations are ongoing.

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, at about 10.50pm on September 23.

Investigations by the University of Canterbury and the accommodation provider, Campus Living Villages (CLV), are underway.

Stepfather Anthony Holland, who last spoke to Pendrous on July 19, has expressed concerns over how long it took to notice something was wrong.

Today, Constable Robert Stokes, an inquest officer for New Zealand Police, revealed the police work done so far to try and establish when he 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 schoolmate 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 stepdad 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.

His cellphone remained logged on to the uni'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 carried out by a forensic pathologist on the day after Pendrous' body was found concluded that he had been dead at least 2-4 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 today's 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.