Families who sent their children to a nursery where a paedophile carried out abuse 'in plain sight' have slammed the council for refusing to investigate the scandal.Vincent Chan, described as 'every parent's worst nightmare', abused children over a seven-year period while working at a Bright Horizons nursery in North London.The 'utterly wicked' 45-year-old was jailed for 18 years in February after he admitted 56 sexual offences - including molesting children, sexually assaulting a woman and taking upskirt videos of girls in his previous job in a primary school.Now three of the affected families have begun legal action against Camden Council over its refusal to investigate whether the nursery group's health and safety systems failed to protect children.In a letter which places the council on legal notice for a potential judicial review, the parents said: 'We as the parents of victims, young children who are some of the most vulnerable people in society, should not have to beg for an investigation like this to be carried out.' Prolific paedophile Vincent Chan has been jailed today after admitting 56 offences The 45-year-old British national has worked in childcare settings for the best part of a decadeThe families are arguing that safeguarding systems failed to protect children at the nursery, allowing for the sickening abuse to occur.Several concerns about the nursery's operations have been raised, including staff shortages, complaints from parents and staff about Chan's behaviour as well as his prolific use of electronic devices.The council has said it is 'currently conflicted' by an 'ongoing statutory review'. The families added in a joint statement: 'Our children were supposed to be safe at nursery. Instead, a predator was able to operate in plain sight for seven years.'We feel there were serious safeguarding failures at Bright Horizons, and those failures should be investigated by the enforcing body, Camden Council. …'This is not only about our families. Every parent who leaves a child at nursery needs to know that, if something goes catastrophically wrong, there is a public authority willing and able to examine whether the nursery operator failed in its duties.'Police officers found Chan's collection of 26,000 indecent images online, including videos of children being raped.He also filmed himself sexually assaulting a number of young girls, aged three and four. Police body-worn footage shows the moment police officers arrest suspended nursery worker Chan in his bicycle helmet Chan was finally caught when a colleague at the £2,000-a-month nursery on Finchley Road raised concerns about his behaviour. Earlier this year, Chan, of Stanhope Avenue in Finchley, pleaded guilty to charges including five counts of sexual assault by penetration, four counts of sexual assault by touching, 11 counts of voyeurism, and 23 counts of taking indecent images of children. One of the images was named 'jailbait', the court heard.He also admitted six counts of outraging public decency - also known as upskirting - one sexual assault on a female by touching a woman's breasts while she was asleep, and six counts of making indecent images of children.The offending dates back around 15 years, and involves at least 20 female victims, although police believe there may be others who have not been identified.A spokesperson for Camden Council said: 'Parents, carers and children are at the heart of everything we do as this Local Child Safeguarding Practice Review (LCSPR) progresses. 'The fact we are participating in this ongoing statutory review, and the matters under consideration, means that we are currently conflicted and cannot begin any investigation into Bright Horizons nursery concerning possible breaches of health and safety legislation.'We appreciate that this is frustrating and upsetting for parents and carers but we will revisit the issue of conflict once the review has completed. 'We also consider that this is an exceptional case that meets the criteria for referral to the Health & Safety Executive, as the national regulator. We did this at the earliest opportunity.'A spokesperson for Bright Horizons added: 'First and foremost, our thoughts remain with the children and families affected by Vincent Chan's horrific crimes.'What happened was a profound betrayal of trust by Chan, and we recognise the deep and lasting impact this continues to have.'We are working with Camden Council and other relevant authorities to support the ongoing CSPR. It would not be appropriate for us to comment on any proposed judicial review at this time.'