The situation is made more complex because TikTok has long faced accusations that ties to the Chinese state may put users’ data at risk.
TikTok has consistently denied this, but earlier this year the social media firm’s US operations were separated from its global business on the orders of US lawmakers.
TikTok told the BBC it believed end-to-end encryption prevented police and safety teams from being able to read direct messages if they needed to.
It confirmed its approach to the BBC in a briefing about security at its London office – saying it wanted to protect users, especially young people, from harm.
It described this stance as a deliberate decision to set itself apart from rivals.
TikTok, which claims to have 30 million monthly users in the UK and more than a billion worldwide, has faced scrutiny over its data protection practices.
The social video platform is headquartered in Los Angeles and Singapore, but owned by Chinese tech giant ByteDance.
Social media industry analyst Matt Navarra said TikTok’s decision to “swim against the tide” is a savvy one – but comes with “pretty combustible optics”.
“Grooming and harassment risks are very real in DMs [direct messages] so TikTok now can credibly argue that it’s prioritising ‘proactive safety’ over ‘privacy absolutism’ which is a pretty powerful soundbite,” he told the BBC.
But Navarra said the move also “puts TikTok out of step with global privacy expectations” and might reinforce wariness for some about its ownership.
E2EE has been hailed by privacy experts as the best way to protect conversations from hackers, corporations and even repressive authorities trying to snoop on users.