Compact self-driving machines could soon take over from human delivery staff as details of Amazon’s latest high-tech project emerge.

The Evening Standard reports that the AVGs, or autonomous ground vehicles, being developed by the US retailer have just been patented in Europe and could once more change the way that consumers receive items they order via safe shopping online.

The vehicles are not just capable of carrying letters and packages from distribution centres to customers’ homes, but also of dropping off the items if there is no one there to answer the door.

People who adopt the Amazon Key service, which is a smart lock that allows electronic access to domestic premises, will have the option of letting AVGs open and close their front door for a more secure drop-off process.

Another advantage associated with using driverless delivery drones is that they will be able to work around the clock, opening up a few more options for people who order via safe shopping online and do not want to wait around at home to receive the package during the day.

The interior of certain AVG models will be built with refrigeration capabilities, allowing for the transport of perishable goods. This feeds into Amazon’s wider ambitions to edge into the grocery delivery market, following its acquisition of Whole Foods last year.

Critics have claimed that the combination of delivery robots with smart locks could create a security hazard for customers, allowing malicious third parties to hack their way into homes across the world without needing a physical key.

This is certainly something that will concern consumers, although there are security issues that face all homeowners and residents and the benefits of Amazon’s new tech might outweigh any of the downsides that have been highlighted so far.