For years the British stereotype of Germans has been that they get the best of everything, from sun-loungers to football trophies – and now it seems they have been achieving the best A-level grades.

Research published by the exam regulator Ofqual has found that German-speaking children in the UK have been sitting A-level exams in their native language – and winning a disproportionate amount of A and A* grades on offer.

The Ofqual research estimated that about 17% of the students taking German A-levels in Britain may be native speakers, and gained about half of the top A* grades on offer – making it harder for non-native speakers sitting the exam.

The new research is good news for pupils taking this summer’s A-levels, with Ofqual suggesting it could increase the number of top grades it hands out, to ensure a level playing field between grades awarded in modern foreign languages and other subjects.

“If the ability of the cohorts is similar to previous years we would anticipate small increases in the proportion of students getting top grades in each subject this August,” Ofqual said in a statement.

The researchers found similar results in French and Spanish, with native speakers gaining higher than average GCSE scores. In Spanish, native speakers are almost 10 times more likely to achieve a grade A or A* than non-native speakers. Native-speaking Germans are 28 times more likely to achieve a grade A, and 11 times more likely to get an A*.

The research comes after complaints from leading schools that modern foreign languages are graded less generously than other subjects. But until now there has been no effort to account for native speakers as exam candidates.

“It is good that the exams regulator is finally getting to grips with important factors that, for many years, teachers have suspected were skewing results in A-level languages,” said William Richardson, general secretary of the Headmasters’ and Headmistresses’ Conference of independent schools.

“In 2014 Ofqual found defects in exam boards’ design of language question papers and now we see – uniquely among A-level subjects – that native speakers have a clear advantage when entering language exams. Together, these particular conditions surely meet Ofqual’s requirement that a ‘compelling case’ has been established to allow an increased proportion of students to be awarded top grades in these subjects.”

In 2016 there were sharp falls in the numbers taking German, French and Spanish at A-level, continuing a trend seen in previous years – with some arguing that the tough grade boundaries were putting students off.

Sally Collier, Ofqual’s chief regulator, said although keeping grades comparable between different subjects was difficult, “the actions we are taking this summer specifically in relation to A-level languages will mean we are better placed than ever to ensure standards in GCSEs, AS- and A-levels are appropriate”.