TikTok officials concede "serious changes" are needed at the social media company in the wake of a spying scandal.
The admission from Australian general manager Lee Hunter came during a fiery hearing on Tuesday of a parliamentary committee probing foreign interference through social media.
It also followed a story, first reported by Forbes, that employees of TikTok's parent company ByteDance allegedly spied on US journalists following negative stories written about it.
Mr Hunter previously denied the incident in an opinion piece last December in the Daily Telegraph, saying the method of surveillance was not possible.
But he told the inquiry "rogue employees" had since been let go by the company.
"This is not what the company stands for. These employees were seeking to isolate the source of leaked confidential company information," he said.
"With this serious misconduct from these rogue employees, serious changes need to happen in the business."
Mr Hunter said TikTok had ramped up efforts on data security following the scandal.
"I want to reassure Australians and in particular Australian journalists their safety and security on our platform is our number one priority," he said.
He stood by the opinion piece, saying he would not categorise the efforts of the employees as spying.
The parliamentary committee is examining how Australian elections and government agencies can be safeguarded online.
TikTok's director of public policy Ella Wood-Joyce rejected claims the app was a national security risk, after the federal government ordered the platform be removed from government devices.
Australia's ban followed the moves of other nations including the US and UK.
"We don't believe there is evidence to support claims TikTok is a national security risk," she said.
"We are very open to government to speak to them about what we do, how we do it and how we're continuing to invest to keep our app and our users safe."
Earlier, officials from Facebook parent company Meta reassured that its new social media presence, Threads, would be monitored for misinformation in similar ways to its other sites.
Meta launched the platform less than a week ago and it is being seen as a direct rival to Twitter.
Since then, more than 100 million users have signed up.
Meta's Australian head of public policy Josh Machin said the approach to Threads to combat misinformation or enforce community standards would be similar to that on its other platforms.
"All of the policies that currently apply on Facebook and Instagram apply on Threads," he told the hearing.
"Anything that would be removed or would violate our community standards on Facebook and Instagram from day one is being removed on Threads as well."
Mr Machin said while the platform was new, work was under way to have fact-checking labels on posts and labels identifying accounts as being affiliated with state-owned media.
Twitter's head of global government affairs Nick Pickles defended recent verification changes made to the platform after its takeover by billionaire Elon Musk.
Changes to the site have allowed users to receive a verification tick on their profile if they sign up to Twitter's subscription model, known as Twitter Blue.
Mr Pickles said the move was a way to crack down on fake accounts.
"There are a number of product changes we are making, designed specifically to make it harder and more expensive to try and manipulate Twitter," he said.
"It's also about raising the cost of bad actors and raising the cost of manipulation."
