An apprentice jockey has tested positive for coronavirus, the British Horseracing Authority has confirmed.
It is the first case of a jockey testing positive in Britain.
The ruling body said the rider, who has not been named, has not ridden for "a few weeks", but did recently attend a race meeting.
Racing returned in Britain without spectators on 1 June after being suspended since mid-March because of the Covid-19 pandemic.
A BHA spokesman said: "Having been notified that an apprentice jockey had tested positive for coronavirus, the BHA has worked with the health protection agency, Professional Jockeys' Association, the jockey and their yard to assist their employer in following government guidance and managing the jockey's recent close contacts.
"A handful of people have been identified and asked to self-isolate for 14 days as a result. Further tests taken by close contacts have not returned any further positive results.
"The jockey in question has not taken a ride for a few weeks, though attended a recent race meeting as a member of stable staff, prior to showing any symptoms and before their positive test.
"It remains important that everyone involved in the sport follows Government and racing guidelines and protocols around social distancing and environment hygiene at all times."
Since the resumption, meetings have taken place behind closed doors, with all attendees required to complete a health questionnaire before each meeting and undergo temperature checks.