Three spectators were ejected from the velodrome in the Olympic Park and one arrested yesterday after the parents of an Australian cyclist were verbally abused in the showpiece venue.
London 2012 organisers confirmed that the incident took place during the electrifying opening evening of racing at "The Pringle" when Britain's male sprint team led by Sir Chris Hoy took gold in a world record and the women's sprint duo, led by Victoria Pendleton, suffered the heartbreak of disqualification.
It is understood the spectators, whose nationality was not disclosed, were accused of shouting abuse at the mother and step-father of Kaarle McCulloch, 24, who partnered Australian cycling veteran Anna Meares to a bronze medal in the women's sprint event.
Australian media reports yesterday claimed footage of the incident had been captured by a television camera and showed four individuals, three men and a woman believed to be British, rounding on Ms McCulloch's mother, Karen, and her step-father Ken Bates.
A spokeswoman for London 2012 organisers Locog said: "Three spectators were ejected from the velodrome on Thursday night. One of them was arrested on suspicion of abusive behaviour. Any such behaviour will not be tolerated."
A source in the Australian athletics squad said it seemed that the ejected spectators had appeared drunk.