WTA chief executive Steve Simon has revealed 'no significant progress has been reached' on securing an investigation into sexual assault allegations made by Peng Shuai.

Peng, a former world number one doubles player, made sexual allegations against China’s former Vice Premier, Zhang Gaoli, at the start of November.

In a post on Weibo, she claimed she was coerced into having sex with Zhang, which began an on-off consensual relationship with the former Politburo Standing Committee member.

Her post was deleted around 30 minutes after it was published, and she subsequently disappeared from public view for three weeks, sparking serious concern about her wellbeing.

When Peng reappeared, she retracted the allegations during an interview with French newspaper L’Equipe and made a number of public appearances at the Beijing 2022 Winter Olympics.

Nonetheless, Simon, who has pulled all tournaments from China and Hong Kong until there is a "full, fair and transparent" investigation into the allegations, remains resolute on the matter.

“A lot of work continues to go on," he told BBC Sport. "We will never stop working on the process. We are strong and we will be resilient.

“What we have said we were going to do so far, we are not going to waver from that. But no significant progress has been reached.”

The withdrawal from China had serious financial consequences for the WTA, but these have been offset by a new title sponsorship deal with medical technology company Hologic.

"They became aware of us because of the stance we took on Peng Shuai," Simon said. "I think it encouraged them that we were someone that they want to talk to."

Simon also discussed his decision to allow players from Belarus and Russia to continue to compete on the WTA Tour.

Following Russia's invasion of Ukraine, the WTA and ATP suspended an event in Moscow in October. But neither governing body has banned individual Russian and Belarusian athletes from competing.

This is in contrast to sports such as athletics, badminton, canoeing and rowing.

Simon conceded the WTA's stance may be impacted by whether Russian and Belarusian players will be able to travel abroad for international events.

The UK Sports Minister Nigel Huddleston said yesterday that Russian players might need to make clear they are not supporters of Vladimir Putin to be allowed to compete at Wimbledon.

"It will force us to change our position, because obviously we have to follow the rules of government," Simon said.

"I feel very, very strongly that again these individual athletes should not be the ones that are being penalised by the decisions of an authoritarian leadership that is obviously doing terrible, reprehensible things.

"But if that happens, which is again part of the overall strategy of making Russia, and Russian citizens, pay the consequence for the decision their government has made, then it won't be something that we support.”

Anastasia Pavlyuchenkova, Veronika Kudermetova and Ludmilla Samsonova are among the Russian players on the WTA Tour.