Facebook needs to be reined in with new laws because of its deliberate failure to protect children’s personal data, safety and mental health, a whistleblower has told The Telegraph.

Sandy Parakilas, who was responsible for privacy and compliance at Facebook for two years, said the company flagrantly disregarded his warnings over other companies’ misuse of children’s data.

He said content content was selected by algorithms in a way that maximised time on the site, and product design was driven by a need to maximise the number of users, irrespective of the harm to people’s well-being through addiction or the promotion of inflammatory disturbing or threatening material.

Mr Parakilas claimed Facebook was run like a “personality cult” centred on Mark Zuckerberg, its founder, who held 50 per cent of the stock, and where, unlike other companies such as Google, there was no dissent or constructive internal criticism of policies.

Mr Parakilas is now chief strategy officer at a US-based group of former Silicon Valley insiders seeking to rethink our relationship with technology.