The results of national tests for 11-year-olds at a London school have been quashed amid claims of cheating.

The head of Hanover School in Islington is to be replaced following the decision on national curriculum tests known as SATs (standardised assessment tasks).

The body which oversees exams, the Qualifications and Curriculum Authority (QCA), said an inquiry had found irregularities in the administration of the tests.

A spokesman said the irregularities meant examiners "could not be confident that the pupils' results represented their own work".

Last month, the school's maths results for 11-year-olds were quashed amid claims that children had been helped with their answers.

Unreliable results

Now the QCA has completed its investigation and decided that the other test results for 11-year-olds - in English and science - are also unreliable.

Hanover's head teacher of 20 years, Cynthia Thumwood, is being replaced and a temporary head has been appointed.

The school governors will decide on Cynthia Thumwood's fate when they meet in the next two weeks.

Hanover is one of Islington's leading schools and had recently been awarded beacon status.

Inspectors had said it was an outstanding primary school.

The annullment will mean the school will have no entry in the performance league tables but officials say the children will not be affected.

League tables

Results for 11-year-olds are used in the compilation of league tables.

This summer, results at several other schools have been the subject of investigations.

Results were annulled at Merstham Community Primary in Redhill, Surrey, because of suspicions that some children had been given extra time to complete the tests.

And the head teacher of Wyndham Primary School in Newcastle-upon-Tyne, Helen Quick, resigned after admitting she had corrected the SATs results of 11-year-olds in maths and science.

Now MPs are to carry out an inquiry into claims that head teachers are cheating on SATs papers because of pressure to keep their schools at the top of league tables.

The Commons' education select committee will look into the issue when MPs return to Westminster from the summer break.