Children from ethnic minorities in Bucks could be losing out on grammar school places because of “racially biased” 11-Plus exams, a campaign group has warned.

Data released in a Freedom of Information request by Local Equal Excellent shows primary school pupils from a Pakistani background are half as likely as their White British classmates to pass the entrance exam for grammar schools in the region.

According to the figures, this includes children classed as ‘high attainers’ according to their Key Stage 2 results.

In three Bucks primary schools where nearly all the children were of Pakistani heritage, of the 46 children categorised as 'high attainers' according to their Key Stage 2 results, only seven passed the 11-Plus exam.

Spokesman Dr Katy Simmons said: “It is particularly disturbing that even high attaining children from Pakistani backgrounds are affected by this bias.”

The figures also showed a similar low pass rate for children of a Black Caribbean background, prompting calls to scrap the tests.

Local Equal Excellent representatives say the data also shows that children from certain ethnic minorities who are from higher social classes and “more well-off homes” are still disadvantaged by the exam

Cllr Rafiq Raja, chair of the Muslim parents Association in High Wycombe said a language difference could be the reason for the low numbers.

He said: “It is the Verbal Ability section of the exam that shows the greatest bias against Pakistani children.

“This is because the tests do not take into account that English is an additional language for many of the Pakistani heritage pupils.”

The figures, which show pass rates for different ethnic groups in 2014 and 2015, show 21.1 per cent of White British children who took the exams last year passed, compared to 10.9 per cent of children from Pakistani and 12.8 per cent of Black Caribbean backgrounds.

More than 55 per cent of pupils from an Indian background passed the tests.

Spokesman Rebecca Hickman said: “The new evidence paints a disturbing picture of a selective system underpinned by clear and substantial bias against children from certain ethnic groups.

“This is entirely preventable discrimination at the heart of our education system.

“So long as grammar schools effectively select on the basis of racial and social factors, the system is not only profoundly unjust, but the whole rationale for selection is fatally undermined.”

The 11-Plus exam was created by the Centre for Evaluation and Monitoring at Durham University and introduced in 2013 by The Buckinghamshire Grammar Schools (TBGS) as a way of making the entrance process “fairer”.

A spokesman at TBGS has been contacted for comment.