Three spectators were thrown out of the Olympic Velodrome after a stream of verbal abuse was directed at the family of Australian cyclist Kaarle McCulloch.
The incident took place Thursday during the track cycling team sprint events. One of the ejected trio was arrested.
McCulloch, who has not commented on the matter, "shared a tear with her parents", said a source close to the cyclist.
McCulloch and Anna Meares had been targeting a gold medal but had to settle for the bronze instead.
Cycling Australia confirmed that an incident took place and the police were involved.
The 24-year-old track star's mother Karen McCulloch and her partner Ken Bates also declined to comment, regarding the incident as "an aberration".
Witnesses said other spectators were appalled by the abuse and alerted security and the police.
"Three spectators were ejected -- one of whom was arrested -- for abusive behaviour at the Velodrome," said a London 2012 spokeswoman.
"We won't tolerate abusive behaviour in our venues."
London's Metropolitan Police said their officers helped staff eject three people from the Velodrome, "following a minor altercation with other spectators".
The trio were two men aged 33 and 27 plus a 37-year-old woman. The police did not reveal their nationality.
The 33-year-old man was subsequently arrested under section five of the Public Order Act, which deals with words and conduct likely to cause fear of harassment, alarm or distress.
He was issued with a fixed penalty notice, meaning he must pay the stated amount or request a court hearing within a given time.
McCulloch has vowed to push on to the 2016 Games, believing she and Meares can take gold in Rio de Janiero.