Revelations child rapist Robert Burrett was investigated for making sexual comments to a disabled schoolgirl - two years before his arrest - have led to urgent calls for a ministerial inquiry.

Opposition MPs and a lawyer involved in the case are requesting an impartial investigator look into how complaints against Robert Selwyn Burrett were missed for years despite the Ministry of Education receiving several concerning reports about his behaviour.

A Christchurch school has come forward with new details about how the ministry and police dealt with a "completely inappropriate" sexual comment Burrett made to a child in 2013 while working as a ministry-contracted special needs driver.

Dark past of playground predator


Before Burrett was arrested in May 2015 for sexually violating a dozen schoolgirls, the Herald is aware the ministry held reports detailing:

* His two drink driving convictions in 2001 and 2007

* A 1993 report from the board chair of Lake Rotoma School outlining how Burrett's tenure as principal led to three staff members resigning and a mass exodus from the school

* A 2013 complaint alleging inappropriate comments and behvaiour by Burrett when he was a special needs bus driver

* A 2014 complaint that a staff member "smelt alcohol" on Burrett during his afternoon school run

* A 2015 complaint that Burrett failed to unload a student from his bus. Burrett reported he was "unaware the student was in the vehicle".

Neither the report from Rotoma school nor the previous complaints about Burrett while he was working as a driver were made public until inquiries by the Herald earlier this month.

Labour's education spokesman Chris Hipkins said there appeared to have been a massive and systemic failure over a long period of time.

"The more that I read about this case, the more alarmed I become. It worries me that even as recently as a few years ago, concerns were being reported and not adequately investigated."

He said it was time for some fresh and independent scrutiny of the whole case.

"Hekia Parata should immediately launch a Ministerial Inquiry, overseen by someone completely impartial. That's the only way we will be able to get to the bottom of how this all went so wrong and ensure that nothing like it can ever happen again."

Catherine Delahunty, the Green Party's education spokeswoman, agreed the case needed to be investigated.

"A review of how the schools' concerns were not acted upon and a plan to prevent this happening again is essential. The failure to act is unacceptable risk to children," she said.

"The situation is not helped by the Government bringing on fees for police vetting services - it's truly false economy at expense of children's safety."

Lake Rotoma School where Robert Burrett had a controversial two-year tenure as principal. Photo / Mike Scott
Lake Rotoma School where Robert Burrett had a controversial two-year tenure as principal. Photo / Mike Scott