Sports broadcaster Clinton Grybas was planning to propose to his long-time girlfriend before he died at the weekend, his parents say.

Mr Grybas, 32, was found dead in his 15th-floor Southbank apartment on Saturday after failing to show for radio station 3AW's Sports Today program, which began at noon (AEDT) that day.

There is speculation he may have fallen and injured himself while sleepwalking.

Friends and family say Mr Grybas was a known sleepwalker and had injured himself once while sleepwalking.

Police have not confirmed the cause of the broadcasters death, which has left his family, girlfriend and former 3AW producer Laurenna Toulmin and colleagues shattered.

News Limited newspapers on Monday reported Mr Grybas's parents, Vic and Sandra, expected him to propose to Ms Toulmin this year.

"He was certainly thinking about it (marriage)," Mr Grybas said. "They were going to Hayman Island for a holiday before the football season and I think he was going to use that occasion to ask the question."

Mrs Grybas said Ms Toulmin and her son were a "perfect match".

"It was just a matter of time. Everyone knew they would get married - all our friends and family," Mrs Grybas said.

"They had paid for the holiday and they were leaving in three weeks for a week on Hayman Island before the football season started."

Friends and colleagues had teased Mr Grybas about when he would propose, his mother said.

"We thought it might be on Laurenna's birthday or at Christmas, but we knew it was going to happen," Mrs Grybas said. "They were such beautiful people and so perfect together. It was a match made in heaven.

"We all kept saying Laurenna should ask him, but she was a traditionalist and she wanted to be asked."

Earlier, Mr Grybas speculated that overwork might have been a factor in his son's death.

"He came home we don't know when," he said. "He's either fallen or collapsed or whatever."

Apartment staff found the broadcaster lying face down on his bedroom floor after his girlfriend alerted management.

Brought to you by AAP © 2024 AAP