In the sentencing memorandum, Mueller said that the lies told by Papadopoulos were so damaging to the Russian Federation investigation that the former Trump adviser once dismissed by a top Trump aide as a "coffee boy", as Inquisitr reported, should spend up to six months in a federal penitentiary.
Papadopoulos is due to be sentenced on September 7.
Greek American George Papadopoulos, a former member of the foreign policy advisory panel to Donald Trump's 2016 presidential campaign, could face up to six months in jail.
In the court filing, Mueller wrote that Papadopoulos' "lies negatively affected the FBI's Russian Federation investigation" and his "lies were not momentarily lapses".
"Instead of telling the truth, however, the defendant repeatedly lied throughout the interview in order to hide the timing and significance of information the defendant had received regarding the Russians possessing "dirt" on Hillary Clinton, as well as his own outreach to Russia on behalf of the campaign", Mueller said in the filing.
Papadopoulos never signed a formal cooperation agreement, and no promise was made to recommend a break on a sentencing.
He had also triggered the initial counterintelligence probe into Russian Federation interference in the 2016 election by revealing to an Australian diplomat, during a night of heavy drinking at a London bar in May 2016, that Russian Federation had political dirt on Clinton. However, the sentencing memorandum states "much of the information provided by the defendant came only after the government confronted him with his own emails, text messages, internet search history, and other information".
Special counsel prosecutors are asking a judge to sentence Papadopoulos to up to six months in prison, according to a court filing on Friday.
Mueller also said Papadopoulos avoided until the last moment telling prosecutors about a cell phone he used in London that had "substantial communications" on it between he and the professor who claimed to know about Russian information on Clinton. Mueller wrote in the statement.
It also reveals Federal Bureau of Investigation agents first interviewed Papadopoulos at the Chicago field office on January 27, 2017. He was questioned for several days and eventually pleaded guilty to lying to the Federal Bureau of Investigation.
While drinking at a London bar in May 2016, he told the Australian ambassador to Great Britain that the Russians had hacked thousands of emails that could damage Clinton's presidential campaign.
One of the big mysteries is who in the Trump campaign Papadopoulos may have told about the Russians allegedly possessing Clinton-related emails. In fact, information the US government received about Papadopoulos was what triggered the counterintelligence investigation in the first place.
After Friday's filing, Papadopoulos' wife, Simona Mangiante, told CNN she felt her husband should pull out of the plea agreement, saying he hadn't had proper representation in the negotiation with the government.