The IOC had revealed it was "looking into" the gesture from Saunders, who raised her arms and formed an "x" after collecting her silver medal at the Olympic Stadium on Sunday (August 1).

IOC Presidential spokesperson Mark Adams said the process had been "fully suspended for now".

The United States Olympic and Paralympic Committee (USOPC) has already announced it will not sanction Saunders for the demonstration, which contravenes the IOC's much-maligned Rule 50.

The IOC has partially relaxed rules on demonstrations and protests at the Olympics but has insisted such acts on the podium are still banned.

"The USOPC and USA Track and Field would like to offer Raven our most sincere condolences," the USOPC said in a statement. 

"Her mother leaves behind an incredible legacy in her daughter for who we are so proud and grateful to call our team-mate.

"Our thoughts and prayers are with the entire Saunders family during this difficult time."

Saunders, who has travelled home to the US, said she was "leaving social media for a while to take care of my mental and my family".

"My mama was a great woman and will forever live through me," the 25-year-old said.

"My number one guardian angel.

"I will always and forever love you."

A separate investigation into Chinese Olympic gold medal-winning cyclists Bao Shanju and Zhong Tianshi, who wore pins depicting the country's former leader Mao Zedong on the podium, is ongoing, the IOC said.

The IOC is still waiting for a report from the Chinese Olympic Committee, which has told the organisation that it will "not happen again", Adams said.

The pins could be seen to contravene rules which prevent the display of political symbols at Olympic venues.