Throughout the investigation, the newspaper allegedly purchased a firearm capable of shooting high-strength pepper spray at speeds of more than 100 kilometers an hour, a stun gun disguised as a torch and a baseball cap with a sharp bladed knuckleduster-type weapon under the brim.
All of the weapons are illegal in the UK under the Firearms Act 1968 and the Offensive Weapons Act 1996.
The stun gun and cap were allegedly purchased by independent Amazon users in the US and Israel respectively, while the pepper spray gun was thought to have been sold by the company directly and sent from a warehouse in the UK.
The weapons were removed from the website after Amazon was alerted of their presence.
A Home Office spokesperson confirmed that the sale of such items was against the law.
"It is an offense to sell any prohibited firearms — including stun guns — and we are increasing the maximum prison sentence for this offence from 10 years to life in prison. Nor should anyone intending to carry these weapons in the UK be in any doubt of their illegality," the Home Office said.
"Anyone caught in possession of a weapon banned in the UK faces being charged with illegal importation of a prohibited weapon, which can lead to a prison sentence.
"The government is taking action with both online and high street retailers to reduce the availability of knives and other prohibited weapons as part of our forthcoming modern crime prevention strategy," the Home Office added.
Speaking about the findings, an Amazon spokesperson said:
"All Marketplace sellers must follow our selling guidelines and those who don't will be subject to action including potential removal of their account. The products in question are no longer available."
There has been debate in Britain in recent times about the availability of accessibility of such weapons, after illegal stun guns were used in a number of high profile crimes, including the murder of British teenager Becky Watts.
Her killer bought the stun gun online, sparking calls for a crackdown on the sale of online weapons over the Internet.