Chan was suspended after a colleague raised concerns about his activities with the children.
The whistleblower complained that Chan had filmed a child falling asleep and set the footage to music, in a bid to entertain his colleagues.
The Metropolitan Police investigation that followed unearthed Chan’s collection of more than 25,000 indecent images of children.
The 46 families taking the legal action are made up of relatives of the victims of his sexual abuse and image-based offending, as well as those whose children were mistreated by him in other ways, including when he made videos of children humiliated or in distress.
In a statement issued by Leigh Day, the legal firm representing them, the families said they believed Chan’s crimes raised “serious questions about how childcare providers recruit, supervise and safeguard staff, and how warning signs can be overlooked over long periods of time”.
“What has happened here is not just about one individual or one nursery.
“In our case, Bright Horizons repeatedly dismissed concerns from parents about Chan’s behaviour, and we believe their consistent culture of brushing concerns aside was key to enabling this catastrophe to happen.”
The statement added that the families were seeking full accountability, initially through the civil case and for Camden Council to investigate Bright Horizons as a corporate entity.
“State institutions must treat this case with the utmost seriousness, act to uncover the full extent of offending, ensure accountability and prevent similar harm in the future,” they said.