Image caption The reporter worked for two weeks at a depot in Avonmouth

A BBC investigation has revealed some agency drivers delivering for Amazon drive dangerously because of pressure to finish their rounds on time. An undercover reporter worked long hours for one of the many agencies supplying Amazon with drivers and earned an amount equivalent to less than the minimum wage. Here Chris* recounts his experience of one day on the road.

On my first day delivering parcels for Amazon I soon found that things like tiredness and toilets aren't taken into account when Amazon plans its delivery routes.

I would arrive at the Avonmouth depot around 07:30.

I only had to travel from Bristol. Other drivers travel from the Forest of Dean and Swindon, one as far as Devon, meaning they have up to a 90 minute drive before they start their shift.

At about 08:30 we were allowed into the warehouse to sort and load our parcels. On a typical day a driver has 150-200 parcels to deliver.

The drivers then collect a handheld scanner, programmed by Amazon with a route to follow.

'Fixed rate'

If all goes to plan the drivers may be on the road by 09:30. Sometimes the parcels aren't ready until much later.

The drivers earn a fixed rate per day for their route but nearly every day there was a problem with the scanner, which delayed me.

I was delivering in Swindon, so the drive from the depot took about one hour. Once out on the road the job is quite straightforward and sometimes enjoyable.

Image caption On a typical day a driver has 150-200 parcels to deliver

If the customer is at home it's easy. Knock on the door, check the name on your scanner, hand over the parcel and move on.

On the whole people are pleased to see you so the customer satisfaction rubs off on you a little. There is no time for chatting though so the interaction with customers is minimal.

'Very slow'

When I tried to help one customer locate her parcel, my agency supervisor barked down the phone: "If it's not in your van forget about it and move on. Stop trying to do customer service. You don't have to be nice."

The customer cancelled the order.

I tried to do the job as quickly as I could while keeping to the speed limit. I was considered very slow.

Other drivers at the depot admitted to speeding. One driver said to get the job done he had to go at 120 mph down the motorway.

Media playback is unsupported on your device Media caption Cody Cooper said she ordered one driver who 'fell asleep at wheel' to stop driving

A few drivers admitted to peeing in a bottle in their van because they didn't have time to find a toilet. Another admitted having defecated in the back of the van on one occasion.

Most days I would get back to the depot at around 20:30. I would regularly notice the same faces that I'd seen in the morning back in the warehouse in the evening so I know I wasn't the only one struggling to finish the round in the expected time.

Like the other drivers at my agency, I was expected to be available for work at least six days per week.

Media playback is unsupported on your device Media caption Amazon agency delivery driver 'went to toilet in back of van'

'Missing my son'

The hardest part of the job was not seeing my family. I would leave the house often before my one-year-old son was up and get back long after he was in bed.

Even in that short time it put a strain on my relationship. I can't imagine how people cope over a long period.

My favourite part of the job, probably because I was missing my son, was delivering parcels which were obviously presents for children.

I would knock and the door and tell the excited adult that they may wish to hide their small person away.

I felt like Father Christmas, but he only works one day a year.

Oxford-based AHC dismissed claims put to them by the BBC as "historic and based on isolated examples which occurred over a year ago" and said: "Since then we have made changes to the way our checks are carried out and taken a number of steps to improve our ways of working."

The firm said it took road safety and the welfare of its contracted drivers "extremely seriously", and that drivers were free to choose when they worked.

Amazon said: "We are committed to ensuring that the people contracted by our independent delivery providers are fairly compensated, treated with respect, follow all applicable laws and drive safely.

"As independent contractors of our delivery providers, drivers deliver at their own pace, take breaks at their discretion, and are able to choose the suggested route or develop their own.

"Our delivery providers have always been expected to pay more than the National Living Wage, and we recently clarified with all of our delivery providers that we expect drivers to receive a minimum of £12 per hour before bonuses, incentives and fuel reimbursements."

* The reporter's name has been changed.