Mr Spry said Meldrum slipped down the steps of his spa, which he described as being eight to 10 feet above ground.
"We don't know what exactly happened. I think he was putting up decorations for his Christmas party, which was next Sunday,'' he told reporters.
"Everyone is pretty hopeful. He has shown signs of recognising people."
Singer Russell Morris was with Meldrum and went home about an hour before the accident happened, Mr Spry said.
Meldrum's brother Brian was with him at the hospital, he said.
An Ambulance Victoria spokeswoman said Meldrum fell from a ladder.
"He fell from a ladder, at some height, he was unconscious when we arrived,'' the spokeswoman told AAP.
Seven Network's Melbourne managing director, Lewis Martin, said Meldrum was a friend and everyone was hoping for good news.
"Molly Meldrum is a national treasure,'' he told reporters.
News of the accident sparked a surge of supportive messages on Twitter and Facebook.
The hashtag #loveyoumolly featured a number of well-wishers and prayers from Australian music and entertainment celebrities.
"Musical Legend. Willie Wonka of Pop. Magical Maestro. Adorable Man. #loveyoumolly Get Well Soon x,'' singer Darren Hayes tweeted.
Danni Minogue tweeted that she's "thinking of him tonight'', while comedian Adam Hills said: "Sending every possible happy and healing thought to Molly Meldrum tonight. 'Don't leave us this way'.''
Meldrum's name is synonymous with music in Australia.
He has hosted TV show Countdown, regularly appeared on variety show Hey Hey It's Saturday and has interviewed some of the biggest names in the music world.
Most recently he interviewed global superstar Beyonce.
His interview sparked an internet rumour that the singer's baby bump was a prosthetic.
Meldrum is famous for his trademark stetson hat and was made a Member of the Order of Australia in 1986 for services to the fostering of international relief and to youth.
- AAP
