Earlier this year, the 32-year-old had ended her 12-month relationship with ''fly-in, fly-out'' boyfriend Elliott Coulson.

As they quickly examined the life and connections of the beautiful and popular 32-year-old Sydney finance industry executive, friends recounted details of the couple's volatile relationship, that had ended shortly after Christmas.

Friends have told Fairfax Media Ms Malonyay had uncovered a web of deceit, including apparent lies about Mr Coulson's whereabouts, his career, as well as his background.

She ended the relationship - but it seems Mr Coulson did not take the news well.

Police have confirmed he was in Sydney in recent days, and while none of her close family and friends had been in contact with her since last Wednesday, it appears Mr Coulson had.

A search of her personal property revealed her mobile phone was missing - and its whereabouts may have helped officers find Mr Coulson.

After tracking him down on the Gold Coast, detectives from the NSW Police Harbourside command joined their Queensland counterparts and entered the foyer of the Marriott Hotel in Surfers Paradise shortly after 11.30am on Wednesday.

But, as they attempted to force their way into his room on the 26th floor to arrest him, it seems Mr Coulson could see no other way out.

He went over the balcony of his room, plunging the 26 floors to the ground outside the lobby.

Police sources have told Fairfax Media the investigation into Ms Malonyay's death was ''pretty much over''.

''The circumstances surrounding the death of the man are being investigated by Gold Coast CIB [Criminal Investigation Branch] but are not considered suspicious,'' a police statement said.

Mr Coulson's death was the culmination of a gut-wrenching 24 hours for Ms Malonyay's family and friends.

Reported missing on Monday when she did not turn up for work at Challenger financial services, police found her body in her flat on McLeod Street, Mosman, about 2pm that day.

Close friend and former flatmate Jason Popkowski said those who knew her were touched by her personality. Her many friends were shocked and devastated when told of her death.

''If you met Kate, she had a permanent smile on her face. She was so bright and bubbly, so respectful to other people, and modest,'' Mr Popkowski said.

Mr Popkowski said Ms Malonyay often worked 12-hour days but spent her weekends socialising with the many friends she had gathered in the three years since she had moved from Avoca Beach on the central coast to Sydney.

Others paid tribute to Ms Malonyay on social media, calling her a ''beautiful soul''.

One man wrote on Facebook: ''Can't stop tearing up thinking I won't get the chance to tell you how much I love you and how very special you are to me … Xxx love you forever Kate xxx.''

Earlier, Harbourside local area command Superintendent Allan Sicard refused to comment on speculation Ms Malonyay had been strangled, saying there was no conclusive cause of death.

He would say only that her body had sustained a lot of bruising.

Detectives will continue to gather evidence from Mr Coulson's hotel room in a bid to piece together exactly what took place.

Family and friends issued a plea for privacy so they could grieve.