Special Counsel Robert Mueller has gathered enough evidence to charge President Trump's ex-National Security Advisor Michael T. Flynn and his son Michael G. Flynn, NBC News has learned.

Citing sources close to the investigation, NBC reported Sunday that investigators are speaking to multiple witnesses over the next few days to gather more information about the elder Flynn's lobbying work.

Investigators are interested in whether Flynn laundered money or lied to federal agents about his overseas contacts, three sources close to the investigation told the network.

NBC News is reporting that Special Counsel Robert Mueller has gathered enough evidence to charge Michael Flynn (right) and his son Michael G. Flynn (left)

Special Counsel Robert Mueller (pictured) has enough evidence to indict Michael Flynn and his son, NBC News reported Sunday

Michael Flynn served as National Security Adviser until February 13, 2017, meaning he was in a White House position for under a month

National Security Advisor Michael Flynn (center) is photographed during his short White House tenure along with Trump adviser Stephen Miller (left) and Jared Kushner (right), the president's son-in-law who also works at the White House

Michael Flynn (center) is photographed leaving a meeting at Trump Tower during the presidential transition along with his son, Michael G. Flynn (right), who was fired from the transition for tweeting about the Pizzagate conspiracy theory

Michael T Flynn (center) sits among administration officials including (from left) Vice President Mike Pence, John Kelly, who's now the president's chief-of-staff, and Jared Kushner, the president's son-in-law who serves as a senior adviser

Michael G. Flynn responded to the news report by tweeting out a photo that showed his father Michael Flynn (second from right) sitting three seats away from Special Counsel Robert Mueller (left) as the two men testified before the Senate Intelligence Committee in 2013

The younger Flynn also made this comment Sunday morning, suggesting 'social justice warriors' were harassing him after he tweeted out a video of a girl being hit by a police officer labeled '"Gender Equality" Has Been Achieved at the University of Miami'

Additionally, Mueller's team is looking into whether Flynn tried to get rid of a rival to Turkish President Recep Erdogan for a fee of millions of dollars.

Sources told NBC that Flynn's son, Michael G. Flynn, could be indicted separately or with his dad.

The younger Flynn worked with his father, including doing work on the Trump campaign, where the elder Flynn was the GOP candidate's main national security adviser.

President-elect Trump fired the junior Flynn from the transition team after Michael G. Flynn used Twitter to spread the Pizzagate conspiracy theory, which involved Hillary Clinton and her Campaign Chairman John Podesta running a child trafficking ring out of the basement of a D.C. pizza restaurant.

The restaurant doesn't have a basement and the story is a lie.

The NBC report provides more evidence that Mueller's team is working at a quick pace, as it's been just under a week since investigators unsealed the indictments of President Trump's former campaign chairman Paul Manafort and his deputy Rick Gates.

Additionally, on Monday, investigators revealed that an unpaid foreign policy adviser for the Trump campaign, George Papadopolous, had pleaded guilty to lying to federal officials.

Two sources told NBC that the elder Flynn said he would cooperate with investigators in order to help his son.

The senior Flynn had held a White House position for less than a month, resigning on February 13 – making him the first high-profile official to go.

Flynn mischaracterized a conversation he had with Sergey Kislyak, the now former Russian ambassador to the United States, telling Vice President Mike Pence he had never discussed sanctions, when he did.

Now former acting Attorney General Sally Yates, a holdover from the Obama administration, warned White House counsel Don McGahn that Flynn's statements were so misleading he could have opened himself up to Russian blackmail.

In a statement from Trump, the president said he decided to let Flynn go as 'a matter of trust.'

The special counsel's office did not respond to NBC's request for comment.

Michael G. Flynn responded to the report by posting a Getty images photo of his father, who was the Defense Intelligence Agency director, sitting three seats away from Mueller, who formerly headed the FBI.

The photo was taken at a 2013 Senate Intelligence Committee hearing where CIA Director John Brennan, Director of National Intelligence James Clapper and Assistant Secretary of State for Intelligence and Research Philip Goldberg also testified.

'A picture worth a thousand words.....go nuts with your comments...,' the young Flynn tweeted.

He had also tweeted out a video that noted '"Gender Equality" Has Been Achieved at the University of Miami,' which showed a young woman being whacked by a cop after she swatted him, as she was being carried by police out of a sporting event.

'So glad this cop didn't hold back,' the junior Flynn commented.

Upon seeing some of the responses, he added, 'The SJW are out in full this morning,' using the acronym for Social Justice Warriors, an anti-liberal dig.

'[T]he disappointment on your faces when I don’t go to jail will be worth all your harassment...,' he added.

The elder Flynn hasn't tweeted since September, when he tweeted out a link to his legal defense fund.