10 CFR §1708.112

1. (a)Counsel appearing before the Board or the Investigating Officer(s) must conform to the standards of ethical conduct required of practitioners before the Courts of the United States.
2. (b)The Board may suspend or deny, temporarily or permanently, the privilege of appearing or practicing before the Board in any way to a person who is found:
   1. (1)Not to possess the requisite qualifications to represent others; or
   2. (2)To have engaged in unethical or improper professional conduct; or
   3. (3)To have engaged in obstructionism or contumacy before the Board; or
   4. (4)To be otherwise not qualified.
3. (c)Obstructionist or contumacious conduct in an investigation before the Board or the Investigating Officer(s) will be grounds for exclusion of any person from such safety investigation proceedings and for summary suspension for the duration of the investigation.
4. (d)At the time of the finding the Board shall issue a verbal or written statement of the reasons supporting a decision to suspend or exclude counsel for obstructionism or contumacy.
5. (e)A witness may have a reasonable amount of time to retain replacement counsel if original counsel is suspended or excluded.