International Olympic Committee President Thomas Bach spoke with Chinese tennis player Peng Shuai over videocall on Sunday, the IOC said.
Peng had disappeared from public view since she made sexual assault allegations against former Chinese vice-premier Zhang Gaoli on 2 November.
Videos and photographs of her emerged on Saturday but the women's tennis tour, the WTA, still had concerns for her well-being.
Emma Terho of Finland, from the IOC athletes' commission, and Chinese IOC member Li Lingwei were also on the 30-minute call.
"I was relieved to see that Peng Shuai was doing fine, which was our main concern. She appeared to be relaxed. I offered her our support and to stay in touch at any time of her convenience, which she obviously appreciated," said Terho in a statement.
The IOC said three-time Olympian Peng had explained that she is safe and well, living at her home in Beijing, but would like to have her privacy respected at this time.
Bach invited Peng for dinner when he arrives in Beijing in January ahead of February's Winter Olympics in the Chinese capital.
The IOC has been criticized in some quarters for not coming down harder on China over the Peng case.
Some Western politicians have even suggested a boycott of the Beijing Games because of her plight, with US President Joe Biden already pondering a diplomatic boycott due to China's human rights record.
Strict coronavirus rules mean few dignitaries would be allowed into China for the Games anyway.