Australian Open authorities have confiscated banners and t-shirts bearing the 'Where is Peng Shuai?' slogan.
Tournament organisers said in a statement that the safety of Peng Shuai was their primary concern, but added that "commercial or political" banners were not allowed inside Melbourne Park.
Fans have launched a GoFundMe page in response.
Two fans arriving at Melbourne Park on Sunday decided to highlight the 36-year-old's situation by displaying banners of support and wearing t-shirts asking 'Where is Shuai Peng'. They saw their items swiftly removed by security, with the tournament later revealing the reason why in a statement to ESPN.
"Under our ticket conditions of entry we don’t allow clothing, banners or signs that are commercial or political. Peng Shuai’s safety is our primary concern. We continue to work with the WTA and global tennis community to seek more clarity on her situation and will do everything we can to ensure her well-being.”
The activists' next step in response was to set up a GoFundMe page - with its aim to see 1,000 fans highlight the issue at the tournament's women's final by wearing the t-shirts. At the time of writing, the page has raised $7,805 Australian dollars of a target of $10,000.