Following the incident, Mrs Mutu ordered staff to tear up the written complaint of the girl and failed to launch an investigation into the allegations.
In a decision released today, the pair were struck off following a Teachers Council disciplinary tribunal hearing in October this year.
In a letter to the tribunal, Mrs Mutu said she believed she was acting in the best interests of the girl by keeping the matter private.
However, the tribunal found that Mrs Mutu's actions were motivated by "a naive wish to brush these things under the carpet in order to protect herself and her husband''.
The pair were both deregistered for serious misconduct and were each ordered to pay $20,000 in costs.
In February, Mrs Mutu was hired by the Ministry of Education as one of 46 student achievement practitioners - "experts'' paid to advise principals.
Labour's Sue Moroney raised Ms Mutu's employment in Parliament in October, and Mrs Tolley responded by saying Mrs Mutu had never been suspended.
Mrs Tolley, who has since lost the education portfolio and instead picked up police, said the education ministry had done "extensive research into the background of the over-500 applicants'' for the 46 student achievement practitioner roles.
A complaint to the Speaker, accusing Mrs Tolley of deliberately misleading Parliament, found there had been no breach of privilege.
Ms Moroney said today that the ministry would have known about the case against Mrs Mutu when she was appointed as an adviser.
"What I want to know is did the minister also know that information?''
She said Mrs Tolley had questions to answer, and called on Prime Minister John Key to examine how his minister had handled the situation.
"Now he's got a Police Minister who either misled Parliament or didn't do her job properly to find out the information,'' Ms Moroney said.
Mrs Tolley would not speak directly to media today.
A spokesman for the minister said Mrs Tolley had not received any advice on individual ministry employees, and reiterated that the Speaker had cleared her of breaching privilege.