The US government has claimed that six people died from taking drugs bought from the illegal underground online marketplace Silk Road.

Silk Road, founded by 29-year-old Ross Ulbricht, was only accessible through the Tor anonymity network (known as the "dark web") and enabled users to buy and sell everything from illegal drugs and stolen credit card details to malware and firearms, or even offer services like hitmen for hire.

Ulbricht, who went by the username Dread Pirate Roberts online, was found guilty of narcotics trafficking, computer hacking, money laundering, conspiracy to traffic fraudulent IDs and creating the website in February 2015, but he has yet to be sentenced.

Now US prosecutors want to introduce new evidence about the people who died from overdoses and get the parents of two of the deceased to testify at the sentencing hearing, which is currently scheduled for 15 May. Ulbricht faces between 30 years up to life in prison.

Hearing adjournment requested

What is the dark web

The dark web is a section of the internet that is not indexed by search engines such as Google and not easily navigated to using a standard web browser.

Accessing the dark web requires specialised knowledge and software tools. An example of this is content only accessible by using the Tor software and anonymity network, which while protecting privacy, is often associated with illicit activities.

Deep web

Generally not purposefully hidden, this part of the internet is not accessible without a known address or access details. Standard browsers can access deep websites. Typically not indexed by search engines such as Google.

Ulbricht's head lawyer Joshua Dratel has asked the New York federal court judge to postpone the sentencing hearing for a month in order to give the defence enough time to examine the US government's evidence and gather expert witnesses in order to refute the claims.

In fact, according to a letter sent to the judge, Dratel claims that the Silk Road marketplace tried to minimise any risks that its buyers and sellers were exposed to and that he has expert witnesses to prove it.

Dratel writes: "In addition, the government's introduction of this issue—the Silk Road web site's alleged responsibility for certain deaths, whether or not from substances purchased from vendors on the Silk Road site—makes highly relevant a related issue: the extent to which the Silk Road web site reduced the dangers of substance abuse, and consciously and deliberately incorporated 'harm reduction' strategies to implement that objective."

The lawyer also claims that the evidence provided by the US government is "woefully incomplete", with missing information including medical records of the six deceased prior to their alleged overdoses, autopsy and toxicology reports relating to two of the individuals, as well as psychiatric records for one of the individuals.

Claims DEA agents sold Ulbricht information

Ross Ulbricht
The FBI has arrested Ross William Ulbricht (aka Dread Pirate Roberts) for operating the illicit Silk Road website since 2011. (Google )

In late March, the US Department of Justice alleged that two Drug Enforcement Agency (DEA) agents stole over $800,000 (£540,000, €745,000) worth of bitcoins from the Silk Road assets confiscated by the FBI.

The individuals are also alleged to have sold information to Ulbricht about the government's progress into the investigation, and Dratel claims in his letter that Ulbricht and his defence were busy mounting a defence against that allegation and have been "blind-sided" by the US government's latest evidence.

"There is zero prejudice to the government in an adjournment of Mr Ulbricht's sentencing. He remains incarcerated and will be through sentencing whenever it occurs," the letter concludes.

"Accordingly, it is respectfully requested that, in order that the defence have a sufficient opportunity to address the government's allegations, which includes scheduling travel and appearances by experts and other potential witnesses, and affording them sufficient time to prepare and submit written materials, Mr Ulbricht's sentencing be adjourned."