According to reports, Winser is leaving after five years at the label to join another British fashion brand. It is thought that Winser's departure and successive appointment will be announced in the next few weeks, said The Times.
Pringle is famous for its diamond-patterned knitwear, which has become popular with celebrities such as Sophie Dahl and Madonna. It has sales of about£100 million a year after being transformed by Winser, a former Marks & Spencer director.
The retailer has stores on London's upmarket Sloane Street and Bond Street and is sold in high-end department stores such as Harrods and Harvey Nichols.