This is a voluntary interview.
Always request a Union Representative and do not answer any questions.
You can leave the interview if they inform you that this is a voluntary statement.
Do not go forward until that has been explained and you have signed the waiver and assurance form from OIG.
Protects the employee from having to choose between self incrimination and job forfeiture for failing to cooperate.
The individual has the right to not be threatened with discharge in order for the OIG to secure incriminating evidence that would be used against them for arrest and prosecution.
Miranda Rights would be applicable here.