LONDON, March 4 (AFP) - Many would have grabbed him for a cheesy photo, but when South African President Jacob Zuma and his entourage swept into a London supermarket, one elderly couple completely ignored him.

Local shoppers John and Catherine Przeslawski -- 92 and 86 respectively -- were so engrossed at the cheese counter they had no idea that one of the world's most powerful leaders was standing right behind them.

Zuma, who is staying with Queen Elizabeth II at Buckingham Palace on his state visit to Britain, was fresh from talks with Prime Minister Gordon Brown at 10 Downing Street.

But the Przeslawskis were oblivious to his presence in the country, let alone his presence right behind them in their local Sainsbury's.

Asked later if they had noticed President Zuma at all, the couple replied: "Who?".

They chuckled at seeing the picture of themselves with their backs turned to the presidential entourage -- which included British Environment Secretary Hilary Benn and Sainsbury's chief executive Justin King.

"We didn't notice anybody, we were too busy choosing our cheese, we didn't see the president at all!" said John Przeslawski.

Zuma visited the Sainsbury's store in Greenwich, south-east London, to learn more about the firm's operations. The high street retailer has strong trading links with South Africa.

He made off with a bad of goodies ranging from English mustard to chutney and jam.

"Mr Zuma was impressed by the selection of South African produce and by the South African wines that we have," a Sainsbury's spokesman said.

"I think he took a couple of bottles off the shelf to have a look at."