Activists and lawyers trying to use the popular short-video service TikTok to gather evidence of war crimes in Ukraine have released a report in which they say they have encountered difficulties in getting data from the platform.

Many videos from Russian soldiers as well as civilians in the war zone are shared on TikTok and can potentially be used as evidence in war crimes investigations and prosecutions, reports Financial Times.

However, TikTok, which is owned by the Beijing-based company ByteDance, deletes almost 90% of such videos and does it so quickly that almost no one sees them.

“How would investigators request information if they didn’t know it ever existed?” International criminal lawyer Raquel Vazquez Llorente told the paper. “This could have catastrophic implications for justice for human rights abuses.”

Independent nonprofits often help investigations by collecting social media posts, but they don’t have the legal authority to demand that TikTok hand over this data.

“We have data protection policies in place related to the war in Ukraine, and we stand ready to respond to requests [International Criminal Court] or other relevant law enforcement agencies, in line with our publicly available law enforcement guidelines, which reflect international legal norms,” reported the representative of TikTok.

But the head of data analysis at the International Criminal Court, David Hasman, told the Financial Times that TikTok’s Chinese ownership made it difficult for the Netherlands-based court, which investigates war crimes and genocide cases around the world, to investigate.

“The way TikTok stores data is very different, and where they store their data, in which countries, obviously it’s very different,” Hasman said. “I would say that’s probably one of the biggest challenges.”

Collecting data from TikTok is more difficult than from Twitter or Facebook, Hasman added.

TikTok dismissed Hasman’s comments, saying it had not received any requests for data from the International Criminal Court. TikTok also stated that they have satisfied the requests of Ukrainian law enforcement agencies.

Diya Kayali, deputy director of Mnemonic, a non-profit organization that collects digital evidence of human rights abuses, also expressed concern about TikTok’s data being stored in China.

“There is a lot of doubt about its association with TikTok being the original, and I feel so right. I have concerns about the security of the data out there, and it is not entirely clear where the interest and influence in the company is coming from… it is particularly concerning that China can access that data directly.”

Earlier this year, Kayali and colleagues reportedly met with TikTok to discuss concerns about evidence of war crimes, but received no “follow-up”.

“It’s very disappointing,” said Kayali. “TikTok’s processes just aren’t developed, and they haven’t figured it out.”