The reading SATs results have been annulled at one of Ipswich’s best-performing primary schools after several words taught in the classroom appeared on the test.

Senior leaders at St John’s Primary School “wholeheartedly dispute” the decision by the Standards and Testing Agency (STA), an executive agency of the Department for Education (DfE).

Some 93% of Year 6 pupils achieved the expected standards in reading, writing, and maths in this year’s SATs, also known as national curriculum tests, DfE data showed on Friday. This was well above the England average of 61%. It was the fifth-best out of 257 primary schools in Suffolk.

See our league table here.

For reading, the school’s progress figure was +1.6 (average), meaning students scored 1.6 more marks on the reading test (out of 50) than comparable peers.

In a letter to parents, seen by this newspaper and authenticated by the school, Roger Clark, chair of governors, said: “Lists of words were provided without meaning and without context over a number of months prior to the tests as is standard classroom practice across the school. During the run-up to this year’s SATS reading test, a number of words shared with your children, also appeared in the test paper.

“The STA have concluded their investigation and stated that ‘The word list will have provided pupils from [St Johns] with an unfair advantage against their peers, and the results are not considered to be an accurate reflection of their unaided abilities…’ As such the STA has decided that the English reading results for all pupils within the cohort will be annulled.”

A school statement issued to this newspaper said: “The school is deeply saddened and wholeheartedly dispute the decision the STA have made regarding the annulment.

“As the decision-making process from the STA is not consultative and there is no right of appeal, the school will move forward and the governing body will review the process for SATs2, to ensure our high standards are maintained.

“The STA also confirmed that our processes for carrying out the administration of the SATs tests before and during the tests adhere correctly to the guidelines.”

Mr Clark apologised to parents and said secondary schools have been informed. Teacher assessment scores will replace the 2017 reading SATs results, he said.

The DfE confirmed the reading SATs results have been annulled.

A spokesman said: “The public must have confidence in the integrity of the exam system and anything that affects this is unacceptable. The Standards and Testing Agency (STA) has a statutory duty to ensure that published key stage 2 test results are a true and accurate reflection of pupils’ abilities.

“Following an investigation into the administration of the 2017 key stage 2 national curriculum tests at St John’s Primary School, the English reading test results were annulled.”