Tesco has refuted allegations that its chief operating officer sold £202,000 of shares in the knowledge the retailer’s stock market value was set to plummet.

Bob Robbins sold the shares in Tesco on January 4, eight days before the retailer’s share price plummeted 16% in one day, wiping £5bn off its value, after it issued a profit warning on Thursday.

A Tesco spokesperson told the BBC: “At the point Bob sold his shares no decision had been taken on the outlook statement and that was the element of Thursday’s statement that moved the share price.

“There was no way Bob could have known that was going to be included in the trading statement. We are confident that Bob was not in possession of any price-sensitive information at the time that the sale was approved.”

Internet director Ken Towle also sold 155,000 shares on December 22.

Tesco reported a like-for-like sales fall of 2.3% excluding VAT and petrol for the six weeks to January 7. The retailer admitted poor range and service had contributed to the poor performance and said it needs “to do a bigger and better job in the UK”.