A TikTok executive has said data being sought by a group of parents who believe their children died while attempting a trend they saw on the platform may have been removed.

They are suing TikTok and its parent company Bytedance over the deaths of Isaac Kenevan, Archie Battersbee, Julian “Jools” Sweeney and Maia Walsh – all aged between 12 and 14.

The lawsuit claims the children died trying the “blackout challenge”, in which a person intentionally deprives themselves of oxygen.

Giles Derrington, senior government relations manager at TikTok, told BBC Radio 5 Live: “We always want to do everything we can to give anyone answers on these kinds of issues but there are some things which we simply don’t have.”

Speaking on Safer Internet Day, a global initiative to raise awareness about online harms, Mr Derrington said TikTok had been in contact with some of the parents, adding that they “have been through something unfathomably tragic”.

In an interview on the BBC’s Sunday with Laura Kuenssberg, the families accused the tech firm of having “no compassion”.

Ellen Roome, mother of 14-year-old Jools, said she had been trying to obtain data from TikTok that she thinks could provide clarity on his death. She is campaigning for legislation to grant parents access to their child’s social media accounts if they die.

“We want TikTok to be forthcoming, to help us – why hold back on giving us the data?” Lisa Kenevan, mother of 13-year-old Isaac, told the programme. “How can they sleep at night?”

Asked why they had not been able to access that data, Mr Derrington said: “This is really complicated stuff because it relates to the legal requirements around when we remove data and we have, under data protection laws, requirements to remove data quite quickly. That impacts on what we can do.”

Data protection requirements to remove data “can impact on what is available”, he said, adding: “Everyone expects that when we are required by law to delete some data, we will have deleted it.

“So this is a more complicated situation than us just having something we’re not giving access to.

“Obviously it’s really important that case plays out as it should and that people get as many answers as are available.”

The lawsuit – which is being brought on behalf of the parents in the US by the Social Media Victims Law Center – alleges TikTok broke its own rules on what can be shown on the platform.

It claims their children died participating in a trend that circulated widely on TikTok in 2022, despite the site having rules around not showing or promoting dangerous content that could cause significant physical harm.

While Mr Derrington would not comment on the specifics of the ongoing case, he said of the parents: “I have young kids myself and I can only imagine how much they want to get answers and want to understand what’s happened.

“We’ve had conversations with some of those parents already to try and help them in that.”

He said the so-called “blackout challenge” predated TikTok, adding: “We have never found any evidence that the blackout challenge has been trending on the platform.

“Indeed since 2020 [we] have completely banned even being able to search for the words ‘blackout challenge’ or variants of it, to try and make sure that no-one is coming across that kind of content.

“We don’t want anything like that on the platform and we know users don’t want it either.”

Mr Derrington noted TikTok has committed more than $2bn (£1.6bn) on moderating content uploaded to the platform this year, and has tens of thousands of human moderators around the world.

He also said the firm has launched an online safety hub, which provides information on how to stay safe as a user, which he said also facilitated conversations between parents and their teens.

Mr Derrington continued: “This is a really, really tragic situation but we are trying to make sure that we are constantly doing everything we can to make sure that people are safe on TikTok.”

• If you are affected by any of the issues raised in this story, support and advice is available via BBC Action Line