Aldi executives once actively avoided journalists at retail industry functions. No longer. A business previously renowned for its secrecy and reluctance to engage with the outside world has transformed itself into a slick PR machine.

Its management team is now only too happy to take anyone remotely interested on a tour of the Aldi store close to the company's UK headquarters in Atherstone, Warwickshire, or boast about the special prices on offer. This week Aldi even became a member of the British Retail Consortium.

Paul Foley, managing director of Aldi in the UK and Ireland, is at the forefront of the marketing charge. After brief stints with Bejam and Iceland, he joined Aldi when the German chain first entered the UK in 1990. He has remained loyal ever since and is enjoying the plaudits Aldi is receiving as it emerges as one of the real winners from the credit crunch.

Aldi stores have no music, fancy flooring or fixtures, yet Mr Foley would not have it any other way. He said recently: “You don't take the shop home, only the food. It is the same product but you are not paying for the decoration. I don't understand why anyone would hold something up and proudly say: 'I paid more for this than I needed to'.”

Mr Foley boasts that although Aldi will typically sell only one type of product, the group is committed to trying to ensure it is among the best available. His management team holds twice-daily tastings to check that the discount chain is holding its own in terms of quality with its nearest competitors.

“We have the best apple pie on the market. We treat it like it is the only one in the world,” he said.

The openness is a stark contrast to the mystery that continues to surround Karl and Theo Albrecht, the brothers who founded Aldi in the postwar ruins of Essen in 1948.

In 1962 they fell out and the business was split into two legal entities, Nord and Sud. The brothers have avoided the spotlight since 1971, when Theo was kidnapped for 17 days and subsequently released for a reported $4 million ransom. He has never spoken publicly since and is thought to live modestly on the German island of Föhr in the North Sea, collecting typewriters.

Mr Foley insists that Aldi's reluctance to engage with the open world is not related to the kidnapping. “It is just their business philosophy that they like to do things simply and quietly.” The quiet life is a thing of the past for Mr Foley - and he is loving every minute of it.