Schools Minister Nick Gibb has said a marker seemed to have leaked a Sats test paper, as he made a statement about an inquiry into the incident.
The Minister said that appeared that one person had leaked the KS2 English grammar, punctuation and spelling test to a journalist.
Mr Gibb said he had spoken to Rod Bristow, President of Pearson UK, to ask for a full explanation of how this mistake occurred. The awarding body had accepted full responsibility for the error and Mr Gibb said in his statement that it had committed to investigating the matter quickly and fully.
Pearson have been asked to look at two issues.
How the material came to be uploaded a day early onto the secure site, something Mr Gibb believed should not have been possible.
Mr Gibb has also asked that all records are examined so that the person who leaked the information can be identified.
However, Shadow Schools Minister, Nick Dakin, said the current testing system was in chaos.
Read more on the TES website.