AP/Amazon
This undated image provided by Amazon.com shows the so-called Prime Air unmanned aircraft project that Amazon is working on in its research and development labs.
The field, situated roughly eight miles south east of Cambridge, was identified as Amazon's largest outdoor drone testing site by Business Insider last month but no drones have been spotted at the location until now.
MailOnline published photos on Wednesday of a drone flying at approximately 50 feet above the field, which contains what appear to be launch pads at either end. The drone was reportedly in the air for at least two minutes.
The publication also published photos of men wearing high-vis jackets and carrying a box that is believed to have been used in the tests.
An Amazon spokesman reportedly told MailOnline: "We are rapidly experimenting and iterating on Prime Air, working to make it a reality.
"This includes controlled testing of many different experimental vehicle components, designs and configurations."
Amazon founder Jeff Bezos revealed plans for Amazon Prime Air in an interview on "60 Minutes" in December 2013. The conceptual drone-based delivery system is currently in development and a number of drone designs have been released.
Amazon wants to use the drones to deliver packages to people's homes and offices in under 30 minutes. It claims the drones will be greener, cheaper, and safer than the vans that are currently used to deliver Amazon packages.
Amazon Prime Air cofounder Daniel Buchmueller said in July that the battery-powered vehicles can rise vertically like a helicopter up to 400 feet before flying up to 15 miles at speeds of 50mph. He said the company is creating 25kg drones that are highly automated and able to carry packages up to 2kg in weight, adding that there are more than a dozen prototypes already made.