Stuart Kelly's parents on the disturbing phone call they received after their son's death.

Warning: This post discusses suicide and may be triggering for some readers.

Stuart Kelly was just 16 when his older brother Thomas lost his life in a hospital bed, just days after being punched in Sydney’s Kings Cross by a young man he had never met.

Two years later, Stuart began college at St Paul’s at Sydney University. His mother Kathy says that less than 24 hours later, “he came out of there a broken human being”.

For months, Stuart hardly left his bedroom, until in July 2016, the 18-year-old – only seven days older than Thomas had been when he’d died – took his own life.

Mia Freedman spoke to Stuart Kelly’s mother in a moving episode of No Fitler. Post continues below.

Now, his parents have shared the disturbing phone call they received in the days after his death.

On Monday night’s 7.30 Report, Stuart’s father Ralph recalled, “he took his life on the Monday morning, on Thursday night I received a call from a very senior person at the college who passed on his condolences to our family and then said he had been contacted by someone in the media about Stuart not sleeping in the college that night.

“He also then said: ‘I have no interest in investigating what happened on the night of the 22nd of February 2016 when Stuart was at the college’, and with that he just hung up.

“As a dad who just lost his second son, I was not ruffled, I was in shock that anybody, (let alone) a senior person at the college, could make a phone call like that to a father who was in grief.”

In a statement, St Paul’s said, “The college is committed to the values of respect and dignity, including equality of respect for women and men, and actions inconsistent with these values are not tolerated”.

The University of Sydney, however, said it would support a coronial inquest into Stuart Kelly's death.

In a report by news.com.au on Monday, Stuart Kelly's parents said they believe their son was the victim of "catastrophic" treatment that likely contributed to his death.

His mother Kelly recalled picking him up from out the front of the Royal Prince Alfred Hospital Medical Centre, where he was sitting in the gutter, just a day after starting college.

"We hadn’t seen him cry since Thomas died," Kathy told 60 Minutes on Sunday night. "So to see he was just sobbing, uncontrollably, and he came home and he went into his room and he basically didn’t come out for the next couple of months, so you can only assume that something catastrophic happened to him that made him feel the way he did."

"With Thomas, he was happy when he died. He was holding a little girl's hand and looking forward to the night ahead and how he was going to kiss her for the first time. Hopefully, he didn't see anything happen or anything coming," Kathy said. "But Stuart was in pain and we couldn't see that and we couldn't help him."

Ralph added, "I think the pain is internalised and it will never go."

 You can visit the Thomas Kelly Youth Foundation here, where you can volunteer or donate.