Waitrose sales have been buoyed by the Rio Olympics and the release of a new Harry Potter book, with sales also rising at sister retailer John Lewis.

Sales at the grocer rose 2.1% to £122.53m in the week to August 6.

Waitrose marketing director Rupert Thomas said: “The start of the Olympics has seen uplifts in sales of Brazilian food and drink, as all eyes turn to Rio for the next few weeks.

“Sales of picanha – a Brazilian-style steak – rose by 20% and Brazilian wine sales powered upwards by 54%. The sporting feast on TV drove sales of quick and convenient suppers, with pizza up by 19%.”

The effect of the summer holidays was also evident, with sales of garden toys up 86% and book sales up 37%. The grocer said this upswing was “due, in no small part, to Harry Potter and the Cursed Child – the first play script ever sold by Waitrose”.

John Lewis

At John Lewis sales rose 7.3% to £73.66m in the week to August 6.

Electricals and home technology had a good week, with sales up 11.2%.

John Lewis shop trade director Maggie Porteous said: “Evidence suggests that customers are making hi-tech purchases ahead of their summer holidays, with cameras and wireless headphones both proving popular. The warm weather also continues to drive sales of home cooling devices, which finished the week up 61%.”

Home sales rose 5.4%, boosted by outdoor living, up 13.3%, and a collaboration with furniture retailer Loaf.

Fashion sales rose 5.4%, benefiting from a strong week in beauty, where sales rose 7.8%, helped by the launch of a Charlotte Tilbury counter in Peter Jones. Menswear also had a strong week, with sales up 11.4%.

Overall, sales rose 4% to £196.18m across the partnership.