FOR more than 50 years, Jock Leyden was a thorn in the flesh of the brutal apartheid regime in South Africa.

His campaign against injustice began in the late 1930s with his cartoons appearing in the Durban Daily News and associated papers in Johannesburg, Pretoria, and Cape Town.

Mr Leyden became South Africa's leading political cartoonist, shrugging off death threats during the Second World War when his drawings attacked the nationalists' support of Nazi Germany.

During the 1950s and 1960s, his drawings sketched a biting insight to the turmoil in Rhodesia, now Zimbabwe. However, it is only now that Mr Leyden has been recognised in his home country.

An exhibition of the work of the former pupil of Grangemouth High School in Stirlingshire, is now on show in Falkirk at Callendar House. The display is an array of political cartoons and caricatures of actors, politicians, and sports stars.

Mr Leyden says the seeds of his artwork were laid by his art master James W Davie at Grangemouth High where he was a pupil from 1921-1924.

The exhibition was the idea of the school's current rector Gerry Docherty whose school has honoured Mr Leyden with a certificate of merit commending his outstanding contribution to art and cartoons and his ''political integrity''.

Mr Docherty became aware of his famous old boy two years ago when he received a copy of the Durban Daily News carrying a tribute to mark Mr Leyden's retirement.

Mr Docherty said: ''It's a pity that Jock's health hasn't allowed him to see his work exhibited in his own country.''

From his home in Durban, Mr Leyden, now 88, said he could not believe an exhibition of his work had been mounted in his homeland. He said: ''For a person who has never met me, what Gerry Docherty has done is just terrific. I can't express my thanks enough.''

Mr Leyden said he sent the paper's tribute to him, and the original cartoons, because of the debt he owed to his old art master.

He said: ''Jimmy Davie really set me off. If it hadn't been for him, my life would have been really different.''

He said that he had ''gone to the limit'' with his anti-apartheid cartoons in a time when working on a newspaper was ''like walking over a minefield''.

He said: ''I used to test the editor. Some editors were a bit petrified. If a cartoon was not published, I regarded it as a bit of a compliment - it was obviously too strong.''

He is now finishing his life story, Drawing My Own Conclusions.