The surprising detail that kept Princess Diana's original red sheep jumper 'in good condition' after 40 years as it sets to make $89,000

Secret behind Princess Diana's original red sheep jumper 'good condition' revealed

Princess Diana's red sheep jumper is to be sold at auction for up to $89,000 (£70,000) after being kept in 'in good condition' by this surprising detail. 

• The original red sheep jumper worn by Princess Diana will be put up for auction at the end of the summer, more than 40 years after the late royal first donned it. 
• The Warm & Wonderful knit, which had been sent back to the company by Buckingham Palace because it was damaged, was unexpectedly discovered by one of its creators in March. 
• In other royal news, We're obsessed with Kate Middleton's cool £135 white trainers as royal hailed 'model of health and fitness'.