The Thirsk rider - who was crowned all-weather champion for the 2019/20 campaign - has enjoyed a highly productive spell since racing resumed on June 1, including claiming his first Royal Ascot win with Dandalla, who he has since partnered to a further Group Two success at Headquarters.
Group Three verdicts aboard Dubai Station and Nayef Road also count among his 63 winners over the last three months - a tally which currently sees him sitting in fourth in the Flat jockeys’ championship standings.
However, he will now be out of action for two weeks while the British Horseracing Authority investigates the matter.
A BHA spokesperson said: “Ben Curtis was ejected from Newmarket this afternoon for breaching the Covid-19 protocols.
“He will not be permitted to enter a racecourse for 14 days from today as per the published Covid-19 requirements whilst the matter is investigated further.”
Trainer Gary Moore was fined £750 earlier this month after breaching protocols at Goodwood, while Mark Gillard and his assistant Steven Hosie were each handed six-week racecourse bans following a hearing on Friday.
The pair were found to have contravened the Covid-19 rules at Newbury on August 15 and will be unable to attend a racecourse until September 26.