Diana and Peter Cooke said they were "angry and upset" after learning they had been referred to social services without their knowledge.
The couple had raised concerns after their four-year-old daughter, Chloe, who has speech problems, twice came home from school with bruising.
Gene Huie, headteacher of Whittingham Community primary school, in Waltham Forest, told them there was no evidence that the injuries had been sustained at school - before secretly referring the case to the child protection team.
The council warned the school that they had insufficient evidence to merit a referral and that it was a breach of guidelines to refer cases to social services without first discussing it with the family.
Despite the warning, the school went on to refer details of a subsequent conversation with Mr and Mrs Cooke, again without their knowledge. The school was again rebuked by the council - but the couple was not informed.

Here's a good example of why schools need local authority oversight.