The owners of champion Winx are expected to confirm she is successfully in-foal to super sire I Am Invincible in the coming days.
With protocols akin to a Royal announcement, connections will wait until the results of the 45-day scan before confirming her pregnancy on Monday.
A report in The Australian suggested Winx had failed to become pregnant the first two occasions she was served.
If the scan is confirmed, Winx will give birth next October.
Her owners Debbie Kepitis, Peter and Patty Tighe and Richard Treweeke, are not expected to sell the resultant filly or colt whose value would be unlimited.
Winx was retired earlier this year with 37 wins from 43 starts.
She won 33 straight races, remaining unbeaten from May 2015 until her final race in April.
Her tally included a world record 25 Group One victories.
