David Seidler, best known for his Oscar-winning writing on The King’s Speech, has died aged 86, according to reports.

The London-born screenwriter, who had a stammer growing up, was inspired to write about the true story of how King George VI overcame his speech impediment with a speech and language therapist.

US outlets reported that the British writer died on Saturday, during a fly-fishing trip in New Zealand, according to his manager Jeff Aghassi.

Aghassi said: “David was in the place he loved most in the world — New Zealand — doing what gave him the greatest peace, which was fly fishing.

“If given the chance, it is exactly as he would have scripted it.”

Seidler won the Oscar and Bafta award for best original screenplay for the 2010 historical drama which starred Colin Firth, who won the best actor Bafta and Oscar for his depiction of the king.

The project was also awarded the best picture Oscar and won best film and outstanding British film at the Baftas.

Seidler was also behind the stage adaptation of the film, which first opened on the West End in 2012.

Throughout his career Seidler wrote on a plethora of other projects including the animated children’s musicals The King And I, Quest For Camelot and Madeline: Lost in Paris.

Seidler won his first Writers Guild award for the 1988 biopic Onassis: The Richest Man In The World starring Raul Julia as the Greek shipping magnate Aristotle Onassis.

He also co-wrote Francis Ford Coppola’s 1988 comedy drama Tucker: The Man And His Dream.