Online fashion chain ASOS has said that a fire at its Barnsley warehouse in June cost it between £25 million and £30 million in lost sales.

The fire in the warehouse, which held approximately 70% of the company’s stock and was its main distribution centre, is thought to have been started deliberately.

"Our UK performance remained strong over the final quarter, with sales increasing 33%. Our International business grew 6% or 14% in constant currency. However, due to the fire at our Barnsley distribution centre, we lost sales during the quarter of between £25m and £30m with a retail gross margin impact of c.200 basis points. After adjusting for insurance proceeds, we expect profit before tax for the year to be in line with market expectations.

“Engagement with our customers remains positive with a 25% growth in active customers and increases in order frequency, conversion rate and average basket value. Sales for the year as a whole increased by 27%.

“In the new financial year we'll make significant investments in our international pricing and proposition, as well as in our logistical infrastructure and technology platform. As a result, we expect profit before tax for the year to 31 August 2015 to be at a similar level to 2013/14.

“We remain focussed on the long term opportunity for ASOS, with £2.5bn of sales as our next staging post".