And the incident has rocked the top rating Channel 10 show.

An Olympic Park groundsman found Mr Neuage's body about 5am last Saturday and notified police.

Mr Neuage, originally from South Australia, had flown in from the US where he was an up-and-coming baseballer signed to the Los Angeles Dodgers' minor league team since 2001.

He played on the Australian junior baseball team between 1997 and 2001, during which time he toured the US and South Africa.

Ms Stewart was eliminated from Australian Idol in the first semi-final on August 11 -- five days before Mr Neuage's death.

They had been a couple, but broke up recently.

The pair had grown up in neighbouring suburbs - Christies Beach and Hallett Cove - about one hour north of Adelaide.

Detectives are investigating the fatal fall, but do not believe it to be suspicious.

A spokesman said no other details could be released because a report was being prepared for the coroner.

Mr Neuage's mother yesterday said she did not want to comment on the circumstances surrounding her son's death until they had been presented to the coroner.

"My son has died and there's an investigation going on," she said.

"There's been a really tragic accident to a promising athlete and there's nothing more I can say."

His father, Terrell, posted a memorial on the Internet, including a poem and his son's baseball card, which pictures him in his Dodgers uniform.

"I will always love you, whatever you are doing, on whatever plane you are," the poem read.

"You are back to where you started. This world was only ever just a stop along the way.

"I am with you always. Your Father."

Wally Marks, Mr Neuage's former baseball coach at the South Australian Institute of Sport, said the pitcher had dreams of playing in the Major League in the US.

"He showed a lot of potential. He had a good work ethic and was a great kid," he said.

Ms Stewart moved to Australia from Malaysia when 13 and has been singing since the age of five.

Her biography on Australian Idol said she was diagnosed with depression at the age of 15 and believed she conquered it with the support of friends and family as well as songwriting.

A spokesman for Channel 10, which screens Australian Idol, declined to comment on the death.

A spokeswoman for Novotel would not say whether Mr Neuage was a guest or visiting Ms Stewart at the hotel.

There was a clamp down on all communication in the hotel's complex with staff in a nearby pub told not to speak to the media.

Meanwhile, Melbourne's Australian Idol semi-finalist Yolande Jackson goes into tonight's knockout round having been hit hard by a throat infection.

Ms Jackson, 26, has been battling a cold for several days, and this week lost her voice.

"At the moment I feel terrible," Ms Jackson, a support worker with SCOPE Victoria, said.

"I have lost my voice. I was sick last week and I am still not well.

"But I have to get over that and focus on what I have got to do.