It is unclear whether probable cause that a willful violation has occurred is a condition precedent to the commencement of a criminal contempt action. Initially, it should be noted that the vast majority of criminal contempt decisions make no mention of such a requirement. However, in United States v. Kelsey-Hayes Co., 476 F.2d 265 (6th Cir. 1973), the court dismissed the case prior to trial on the basis of its determination that there was a lack of probable cause that a willful violation had occurred. The court in In re United Corporation, 166 F. Supp. 343 (D.Del. 1958), held that it was within the court's discretion to require a showing of probable cause before appointing an attorney to prosecute a criminal contempt action which was initiated by a private party, rather than the United States.
[cited in USAM 9-39.000]