Labor senator Kimberley Kitching had been under immense stress due to a bitter factional brawl within the Victorian branch of the Labor Party, and her political mentor Bill Shorten is questioning whether it could have contributed to her sudden death.
An emotional Mr Shorten led tributes to the 52-year-old on Friday morning, after Senator Kitching died from a suspected heart attack in Melbourne late on Thursday afternoon.
Mr Shorten was a close friend of Senator Kitching and her husband, Andrew Landeryou, and had been called to the suburban street in Strathmore where her body lay.
"She was in the next suburb when she passed," Mr Shorten told ABC RN.
"So my wife Chloe, who's a close friend of her, known her from school — we just immediately drove over.
"And we sat with a couple of other of dear friends of Kimberley and Andrew on the side of the road as we waited for the undertaker's van to turn up."
Senator Kitching was facing a preselection challenge ahead of the looming federal election, with members of Victorian Labor's right faction refusing to endorse her spot on the party's Senate ticket as recently as Tuesday.
"Preselection is never easy," Mr Shorten said.
Mr Shorten had endorsed Senator Kitching to replace former senator Stephen Conroy, who quit politics a couple of months after the 2016 election.
"You can never dial forward and predict back what's going to happen," Mr Shorten said, choking up.
"But you do wonder if she would've been better off never going near politics.
"But you don't know, so all you can do is think about the good things."
Albanese describes 'tremendous shock' for party
Opposition Leader Anthony Albanese was questioned about whether he believed the preselection dispute affected her.
"Politics is a difficult business — there are pressures on people in politics and that is part of what we do — but I certainly think that this was totally unexpected," he told the ABC.
"No-one could have anticipated this. And people were ringing each other, I think, multiple times to get confirmation because it was such a shock.
"Kimberley looked fit, she had got fitter in recent times, and there was no history of a heart condition and that is why it's such a tremendous shock for the entire Labor family today."
Mr Albanese described Senator Kitching as a "vivacious character".
The tributes for her came from across the political divide, with senior members of the Coalition praising her contribution to the Senate.
"I'd consider Kimberley a friend," Nationals Senate leader Bridget McKenzie said.
"She was such an intelligent, irreverent woman and senator, and a fierce patriot for our country."
And former Victorian Labor MP, and Kitching ally, Michael Danby paid tribute to Senator Kitching's contribution during her time in parliament.
“Kimberley Kitching ought to have been a future Australian foreign or defence minister," he said.
"In but six years in the Senate she already had a national and international reputation.
Defence Minister Peter Dutton said he too was very close with Senator Kitching, and had planned to catch up with her while on holiday in Queensland over summer.
"She was a real hawk on national security matters and I think the Parliament will miss her," he told Channel Nine.
"I think our country's poorer for her passing."
Senator Kitching's work in foreign affairs, and her advocacy for an Australian Magnitsky Act, have garnered widespread praise in light of her death.