A fire that caused "substantial damage" to the warehouse of online retailer ASOS is being treated as arson, police have said.
The blaze at the warehouse in Barnsley was attended by 10 fire engines and caused the company to cease trading.
South Yorkshire Police said the incident was now being treated as deliberate after initial investigations had been carried out.
Around 500 workers were safely evacuated from the building after the fire broke out just before 10pm last night.
A statement on the ASOS website says: "Dear Customers, we have pressed pause on the ASOS website, this is due to a fire in our Barnsley distribution centre in the early hours of Saturday morning.
"Thankfully no one was hurt and we expect to be back to normal for you in the next day or so. So please hold on to your orders, we will be back with you soon"
The warehouse is said to contain over 10 million boxes of packaging and is more than 60,000 square metres in size.
Investigating Fire Officer for South Yorkshire Fire and Rescue, Simon Rodgers, said: "The fire involved four floors of the warehouse and the blaze was contained in the area of origin by firefighters.
"ASOS staff had a good evacuation process in place which assisted the emergency services and allowed the fire to be brought under control more quickly."
Three of the fire engines that attended the incident on Park Spring Road had been called in from West Yorkshire Fire and Rescue.
Michael Dugher, MP for Barnsley East , tweeted last night: "Huge thanks to the brilliant crews from @SYFR + @West_Yorks_FRS for tackling the @ASOS fire. They do a magnificent job. Glad no one hurt."
The retailer sells fashion and beauty products around the globe and last year made sales of over £750 million.
Statement From South Yorkshire Fire And Rescue
A criminal investigation has been launched to establish the cause of a fire last night (Friday, 20 June 2014) at the ASOS warehouse in Grimethorpe, Barnsley.
South Yorkshire Police are now treating the incident as deliberate, after initial investigations were carried out this morning with South Yorkshire Fire and Rescue.
Emergency services were called to the warehouse in Park Spring Road at around 10pm last night to reports of a blaze.
Around 500 workers were safely evacuated from the premises and nobody was injured.
Investigating Fire Officer for SYFR, Simon Rodgers said: "The fire involved four floors of the warehouse and the blaze was contained in the area of origin by firefighters.
"ASOS staff had a good evacuation process in place which assisted the emergency services and allowed the fire to be brought under control more quickly."
Anyone with information should call South Yorkshire Police on 101, quoting incident number 1210 of Friday 20 June 2014.
Alternatively, call Crimestoppers, anonymously, on 0800 555 111.