Ocado suffered at the hand of Amazon yet again last week, when the e-retail giant said it was expanding the catalogue of products on offer as part of its new Amazon Pantry service.

The announcement, embedded in a Guardian interview with Amazon UK chief executive Christopher North, was followed by a sudden 3% drop in Ocado’s share price.

North said he was “happy with the early numbers” Pantry had generated and that the online retailer would be “adding a lot of new products” in the new year.

Amazon Pantry, which is exclusive to Amazon Prime members, allows shoppers to fill 20kg boxes with groceries from a selection of more than 4,000 household goods.It was launched in November of last year.

Ocado experienced similar issues last July, when a 7% shares tumble was triggered by rumours that Amazon was planning to bring its Amazon Fresh service to UK shores.

The company’s shares continued to suffer for the remainder of the year falling 40% from a high of 471p in mid-July to just 280.6p at the time of writing (5 January 2016).

However its operating figures have remained firmly in the black after its 2014 figures saw Ocado turn a profit for the first time since 2000; its preliminary results next month are expected to show a 17% boost in turnover.

Trials of Amazon Fresh in London and Birmingham late last year suggested that the e-retailer may well be planning nationwide launch, which could prove to be a threat to more household names than just Ocado.

While he described the online grocery sector a “challenging and competitive” environment, Ocado chief executive Tim Steiner seemed unmoved by falling share prices and increasing noise about a UK-wide Amazon Fresh service in the company’s Q4 results.

He said: “Order growth remains strong with average orders per week now exceeding 200,000. This reflects the ongoing shift to online grocery shopping and the specific value customers place on Ocado's leading proposition, offering the highest service levels and widest range.

“We anticipate the retail environment to remain challenging, but expect to continue growing sales ahead of the online grocery market.”