German grocer Lidl's has announced the abrupt resignation of its chief executive, Wilfried Oskierski, but was quick to deny had anything to do with the bugging scandal in which the retailer was recently embroiled.

Reports suggest that Oskierski's resignation may be related to friction with board president Klaus Gehrig.

A company spokeswoman said that a replacement has yet to be found, but purchasing chief Heinz Holland and head of German operations Frank Michael Mros have both been tipped as possible successors.

• Lidl is set to open its 500th UK store in November 2008.