Comedian Jack Whitehall left pupils at a Birmingham school starstruck when he turned up to dish out their GCSE results.

The star, who plays young teacher Alfie Wickers in BBC sitcom Bad Education, described his own results as "mixed" before presenting three students at Greenwood Academy with sealed envelopes containing their much-anticipated grades.

Despite his upcoming role in the Bad Education movie, Mr Whitehall admitted he had "bombed in drama" at school.

He told the students: "I remember being very nervous but you just need to keep telling yourself it's not the end of the world if you mess up."

As one student opened his results live on BBC TV news, Mr Whitehall exclaimed he had "smashed it out of the park".

Principal Harry French has overseen the transformation of the Castle Vale school from a failing performing arts college to one of the fastest improving in the country.

He said: "The kids here worked so incredibly hard this year. They have turned it around. They have worked so hard to make sure they succeed."

It comes as figures released by the Joint Council for Qualifications show that there was a slight improvement to GCSE pass rates in the West Midlands overall - but the number of top A* and A grades have dropped.

In total, 521,931 GCSEs were taken in the region - 66.9 per cent were A* to C, a 0.2 per cent increase on last year.

And 18.4 per cent of GCSEs taken in the region achieved A*s or As, a drop of 0.3 per cent compared to the 2013/14 academic year.

Colin Diamond, interim director of education at Birmingham City Council, said: "I would like to congratulate our young people who have worked so hard to achieve these great results in their GCSE exams and their equivalents and I wish them every success in the future.

"And a huge thanks to their teachers, parents and friends for the quality of teaching and the strength of support given to them in the years leading up to this important milestone."

Among the success stories was Park View Academy in Alum Rock - one of the schools at the centre of the Trojan Horse scandal.

It was placed in special measures by Ofsted in April last year following an alleged plot by hard-line Muslims to take control of governing bodies.

The number of youngsters achieving three or more A*s or As rose to 27 per cent - up six per cent on last summer. Sixty-three per cent of students achieved A* to C in English language, while in maths the figure was 66 per cent.

Interim chairman of governors Amran Majid said: "After a very challenging year, Park View students have done themselves extremely proud."

And another failing school - Al Hijrah in Bordesley Green, which is in special measures and £3 million in debt - also saw results soar.

It had 81 per cent of its pupils achieving five GCSEs grades A* to C, including English and maths - an 11 per cent increase on this time last year.

Meanwhile, Arthur Terry School in Sutton Coldfield saw 80 per cent of its students gaining five or more GCSEs grades A* to C including English and maths.

A statement by joint head teachers Richard Gill and Neil Warner said: "These results are only possible as a result of the outstanding relationships and support from all members of the school community."

Plantsbrook School in Sutton Coldfield celebrated a plethora of top grades. Out of all the GCSEs sat by pupils, 22 per cent achieved A*s or As.

Headteacher Tracy Campbell said: "Students and their teachers have worked very hard for these results and they thoroughly deserve their success."

And King Edward VI High School for Girls in Edgbaston had its best results in over a decade - with 92 per cent of its GCSEs being an A* or A.

"The girls have done brilliantly" said principal Ann Clark. "These results reflect their hard work and determination, together with the dedication of the staff."

Students at schools run by the Ark chain of academies - which is next month set to take over two Birmingham schools at the centre of the Trojan Horse scandal - are also celebrating their best results to date.

The number of pupils achieving five A*- C grades, including English and maths, soared to 51 per cent at Ark Kings Academy in Kings Norton - up five per cent on 2014.

And it was 65 per cent of pupils who achieved the same benchmark standard at Ark St Alban's Academy in Highgate.