Athletes traveling to next month's Beijing Olympics were warned on Tuesday about speaking up on human rights issues while in China for their own safety by speakers at a seminar hosted by Human Rights Watch.

Rights groups have long criticized the International Olympic Committee (IOC) for awarding the Games to China, citing the treatment by the Chinese government of the Uyghurs and other Muslim minority groups, which the United States has deemed genocide. China denies the allegations of human rights abuses.

"There's really not much protection that we believe is going to be afforded to athletes," Rob Koehler, the director general of the Global Athlete group, said in the seminar. "Silence is complicity and that's why we have concerns.

"So we're advising athletes not to speak up. We want them to compete and use their voice when they get home."

Rule 50 of the Olympic Charter states that "no kind of demonstration or political, religious or racial propaganda is permitted in any Olympic sites, venues or other areas."

"Chinese laws are very vague on the crimes that can be used to prosecute people's free speech," Human Rights Watch researcher Yaqiu Wang said.

"People can be charged with picking quarrels or provoking trouble. There are all kinds of crimes that can be levelled at peaceful, critical comments."

Noah Hoffman, a cross-country skier who represented the U.S. at the 2014 and 2018 Winter Games, said the American team was being shielded from questions about human rights.

"I feel fear for my teammates going to China," Hoffman said. "I know my teammates are being shielded about questions on these issues for their own safety.

"We should never be having to protect athletes from speaking out about issues that they think are really important.

"My hope for athletes there is that they stay silent because they are not only going to be prosecuted by the Chinese authorities, but they could also be punished by the IOC."

Concerns about data privacy and spying at the Games were raised on Tuesday when a smartphone app built by China to monitor the health of attendees was reported to contain security flaws.

"When it comes to surveillance, we know it's there," Koehler said.

"There are reasons that several countries have come out and asked athletes not to bring their own mobile devices. Any person of a sane mind who hears these things must have concerns."

Speaking during a virtual briefing on Wednesday, Yang Shu, deputy director general of Beijing 2022's International Relations Department, said that athletes could face recriminations for any conduct violating "the Olympic spirit."

"Any expression that is in line with the Olympic spirit I’m sure will be protected and anything and any behavior or speeches that is against the Olympic spirit, especially against Chinese laws and regulations, are also subject to certain punishment," Yang said.

Cancellation of accreditation is a potential punishment in line with guidelines in the organizers' playbook, he said during the event hosted by China's embassy in Washington. However, the playbook mainly addresses COVID-19 prevention measures and does not address issues such as speech or protest.

The IOC said in an emailed response to a request for comment that the Olympic body "recognizes and upholds human rights  as enshrined in both the Fundamental Principles of the Olympic Charter and in its Code of Ethics" at all times.

The Winter Olympics are set to begin on Feb. 4. Several countries including the United States, Britain, Japan and Australia have announced diplomatic boycotts of the Games over concerns about human rights in China.