Online shopping giant Amazon has been found guilty of dispatching potentially dangerous goods to be transported by air.
The items included lithium ion batteries and flammable aerosols and were shipped between January 2014 and June 2015. All were found by Royal Mail screening staff before reaching the planes.
A jury at London's Southwark Crown Court found the company guilty of four counts of causing dangerous goods to be delivered for carriage in an aircraft in breach of air navigation rules, the UK Civil Aviation Authority (CAA) said.
The prosecution for the dangerous goods found in Amazon UK Services Ltd shipments was brought by the CAA under the Air Navigation (Dangerous Goods) Regulations 2002.
It outlines how dangerous goods must be handled when transported by air. This includes how they must be classified, packed, marked, labelled and documented - as well as the dangerous goods training which must be completed by the persons sending them.
Amazon UK Services Ltd is to be sentenced at the same court on Friday.
After the hearing, the CAA's general counsel Kate Staples said: "The safety of aviation and the public is paramount and that's why there are important international and domestic restrictions to prohibit the shipping of certain goods that pose a flight safety risk.
"These dangerous goods include lithium batteries, which are banned from being transported as mail or cargo on a passenger aircraft unless they are installed in or packed with equipment.
"We work closely with retailers and online traders to ensure they understand the regulations and have robust processes in place so their items can be shipped safely.
"Whenever issues are identified, we work with companies to make sure those issues are addressed appropriately. But if improvements are not made, we have to consider enforcement action and as this case demonstrates, we are determined to protect the public by enforcing the dangerous goods regulations."
An Amazon spokesman said: "The safety of the public, our customers, employees and partners is an absolute priority.
"We ship millions of products every week and are confident in the sophisticated technologies and processes we have developed to detect potential shipping hazards.
"We are constantly working to further improve and will continue to work with the CAA in this area."