Former White House national security adviser Michael Flynn is worried over the potential legal exposure of his son Michael G. Flynn in the ongoing investigation by special counsel Robert Mueller into Russian interference in the 2016 presidential election.

The concern for Flynn Jr., who is also under probe by Mueller like that of his father, was confirmed by multiple sources familiar with the matter to CNN.

Mueller's focus on Flynn Jr. might be a tactic to coerce Flynn into cooperating with the investigation, a report said citing some legal experts.

The senior Flynn's concern would "factor into" how he engages with Mueller's investigation. Flynn's wife Lori too has expressed the same concern about Flynn Jr.'s possible legal exposure, CNN reported citing a person who knows the family.

Flynn Jr. might be in possible danger as Mueller has already collected enough evidence to bring charges against him as well as his father, according to an NBC News report from Nov. 5. and this evidence relates to the Flynns' undisclosed lobbying efforts for a businessman having ties with the Turkish government in 2016, while Flynn was still an adviser to then presidential candidate Donald Trump.

During that time, Flynn Jr. was his father's chief of staff, and appeared to have worked with him in his lobbying work.

During the interviews conducted by special counsel investigators, there were questions pertaining to business dealings of Flynn and his son. The questions were in relation to their firm's reporting of income from work overseas, two witnesses interviewed by the team told CNN.

Flynn Jr. could be indicted separately or at the same time as of his father, NBC reported citing three sources familiar with the investigation.

Two of the sources also added that if Flynn tries to cooperate with investigators in the probe to help his son, it could be beneficial for him as well, as there are chances Flynn's legal consequences could be reduced too.

The pressure on Flynn is an indication that Mueller is trying his best to move the investigation at a rapid and steady pace.

Flynn Jr. tweeted a video Sunday that showed three Miami-Dade officers carrying a drunk woman out of a stadium in Miami. In reply to the video he tweeted: "The SJW are out in full this morning....the disappointment on your faces when I don’t go to jail will be worth all your harassment." The tweet can be seen as a subtle taunt to Mueller.

This kind of tweet was condemned by former federal prosecutor Renato Mariotti on Monday. He called Flynn Jr.’s behavior "unbelievable," according to Raw Story.

"It’s something I have not seen before in my experience as federal prosecutor," Mariotti said. "Not only in my cases, but observing other cases. Typically when people are facing a federal indictment, they’re crapping their pants, so to speak. They’re very concerned. It is a big deal. It’s a scary thing. Usually, you are not trying to upset the prosecutor. You’re usually trying to see if you can convince them not to indict. So this sort of thumbing your nose at the prosecution, it tells me that either these people are extremely foolish or they are angling for a pardon in some way."