"A lot of bleeding was involved and unfortunately they were unable to stem the flow, that was the morning report I received," Rix told ABC Radio.
The exact cause of death has been reported as an aortic aneurysm - a swelling in the wall of the large blood vessel that carries oxygen to the heart.
English, known for his breakthrough stage role in Jesus Christ Superstar, was due to tour Australia from May starting in Perth, but was forced to cancel several shows earlier in the week due to "unexpected ill health".
"Jon is currently hospitalised and waiting to undergo a small operation, but is expected to make a full recovery over the coming weeks," said a post on his official Facebook page last week.
"We are very hopeful of working with the venues to reschedule both shows as soon as practical for all concerned and thank everyone for their understanding."
Just over a week later, the singer cancelled yet another headline performance at the Beaumont St Carnivale event in Newcastle.
"He apologies to all of his fans who were looking forward to the day, but assures everyone he will be back to full health and rocking out on stage with you all again very soon (he is in fact itching to do so!)"
English won the 1979 Logie Award for Best New Talent in Australia for his role in TV mini-series Against the Wind.
He also won four ARIA awards throughout his career - for his album Turn the Page, his musical Paris and a production of The Pirates of Penzance, in which he starred.
The Hollywood Seven singer was set to perform in Orange in NSW's central west in April before touring Australia as part of the Rock Show Oz Edition, which was to kick off in Perth in May.
- AAP
