Washington (CNN) Former White House national security adviser Michael Flynn has expressed concern about the potential legal exposure of his son, Michael Flynn Jr., who, like his father, is under scrutiny by special counsel Robert Mueller, multiple sources familiar with the matter tell CNN.

Flynn's concern could factor into decisions about how to respond to Mueller's ongoing investigation. The special counsel is looking into Russian meddling in the 2016 campaign as well as the business dealings of key campaign advisers to President Donald Trump.

Flynn's wife, Lori, shares his concerns about their son's possible legal exposure, according to a person who knows the family.

Interviews conducted by special counsel investigators have included questions about the business dealings of Flynn and his son such as their firm's reporting of income from work overseas, two witnesses interviewed by the team told CNN. The Foreign Agents Registration Act (FARA) requires people acting as agents of foreign entities to publicly disclose their relationship with foreign countries or businesses and financial compensation for such work.

Flynn Jr., who served as his father's chief of staff and top aide, was actively involved in his father's consulting and lobbying work at their firm, Flynn Intel Group. That included joining his father on overseas trips, such as Moscow in December 2015. During that trip, Flynn dined with Russian President Vladimir Putin at a black-tie gala for the RT television network, which US intelligence views as a Russian propaganda outlet.

Read More