TOKYO (REUTERS) - The International Olympic Committee (IOC) is still waiting for a formal explanation from the Chinese National Olympic Committee as to why two gold medallists wore badges featuring the head of the country's former leader Mao Zedong on the podium at the Tokyo Olympics.

The Chinese have said they will provide a report "soon" and assured the IOC there would be no repeat.

Another investigation into the actions of US shot-putter Raven Saunders has been suspended after the death of the athlete's mother, the IOC said.

Silver medallist Saunders had raised her arms in an X above her head on Sunday (Aug 1), which she later indicated was an expression of support for the oppressed.

The United States Olympic and Paralympic Committee said the gesture did not breach its rules as it was a "peaceful expression in support of racial and social justice (that) was respectful of her competitors".

Cyclists Bao Shanju and Zhong Tianshi wore the badges featuring the head of China's former leader during a medal ceremony on Monday, in a potential breach of Olympic rules on the display of political paraphernalia.

The duo wore the badges, commonplace in China for half a century but a potential breach of Rule 50 of the Olympic charter, after retaining the women's cycling team sprint title at the Izu Velodrome.

While the IOC last month relaxed Rule 50 to allow gestures, such as taking the knee on the field of play provided athletes do so without disruption and with respect for fellow competitors, it has banned any such gestures on the podium.