A 77-year-old man from Weymouth says his life has changed after appearing on a documentary to find out more about his heritage and the secrets surrounding his birth.

Local man John Stockley will be appearing on the Channel 4 documentary Britain's Secret War Babies which airs on Channel 4 tonight, and follows the true stories of two children of African-American GIs from the Second World War and British mothers.

The documentary follows two people, Mary and John, both of whom were born illegitimately to white British mothers and African-American GIs during the Second World War.

In this emotional one-off documentary, presenter Sean Fletcher helps John to unravel the secrets and lies surrounding his birth and to track down any surviving relatives.

He explores top-secret documents revealing the anxiety of the UK government about the arrival of African American GIs, and the frantic official reports about their children with British mothers.

Ahead of the programme airing, John spoke to the Echo about the documentary and what it was like growing up in Dorset.

Dorset Echo: John Stockley as a young man working in WeymouthJohn Stockley as a young man working in Weymouth

John was born in Weymouth on May 7, 1945, to his mother Eva, after she had had an affair with an African American GI. His mother didn't keep in contact with John's real father and never saw him again after he left to go to war in France.

John said: "My stepfather came back in 1946 and was greeted with me, a black child. In retrospect he should have gone then, he should have left me, because he never forgave my mother for doing what she did.

"When he came back my mother had opened her guest house and Les, my stepfather, had decided that to save embarrassing questions from guests, he would send me off to his parents. Which was the best thing he ever did because my step grandmother and step grandfather were fabulous people."

Up to the age of about 10 John was brought up by his step-grandparents near The Fleet which he described as an 'idyllic' place to grow up.

Nearly three million American soldiers, or GIs, passed through Britain during the war. It is estimated that 240,000 of them were African American – 8,000 of whom were stationed in and around Weymouth, Dorset, on the strategic South Coast.

Around 2000 such children were born between 1942 and 1946, increasing the Black population of the UK by almost 30 per cent and making John part of the first significant generation to be born Black and British in the years before Windrush.

John said that through the documentary he was able to look at documents which revealed that prominent leaders and figures were concerned about black soldiers being in the UK and the mixing of the races. John said that there were 16 mixed race children in Weymouth and Portland when he was growing up.

"It's hidden history," he said. "When the Americans came it was a segregated army. The white soldiers would live in one camp and the black soldiers in other camps."

John said the documentary had changed his life after it helped him find out more about his biological father and helped him to discover and meet lost relatives he never knew existed.

He added: "I went out as an only child, I've come back as one of nine."

John is a well-known figure in the county and spent much of his life working in the area as a chimney sweep after taking over his step-father's business, Electric Sweep, in the 1980s, which is still operating today and is now run by John's son.

He added: "It's still going and it's highly successful. We're probably one of Weymouth's oldest established businesses."

The documentary Britain's Secret War Babies will air on Channel 4 at 9pm on Wednesday, August 17.