At a news conference here and in a court affidavit, immigration and F.B.I. officials and the United States attorney, Thomas E. Scott, described a year of investigating Mr. Faget after suspicions were raised by a routine investigation.
"We asked them what was going on, and they said it was just a routine investigation.
A routine investigation by the department found the main cause of death was heat stress.
The company said it had found the problems at the unit, the world's largest bus manufacturer, during a routine investigation.
The inquiry, which a spokeswoman for the options board called "a routine investigation into unusual trading," began on Monday.
MMF diagnosis requires muscle biopsy, an invasive procedure not suitable for the routine investigation of all patients with musculoskeletal pain.
A grand jury can be used to obtain sworn testimony, to obtain evidence not available through routine investigation, and to seek indictments.
California lottery officials, yet to be informed that a ticket had been reported stolen, nevertheless began a routine investigation, conducted for all winnings of $600 and up.
In a routine investigation, Bavarian prosecutors had entered his flat in February 2012 and found works by Matisse (pictured), Chagall, Beckmann, Nolde, Picasso and other masters.
The death of the student, Satto Tonegawa, son of Susumu Tonegawa, is under routine investigation by the state police and the Middlesex County district attorney's office.
The accusations surfaced last week during a routine investigation into a recent shooting attack on a former militant, Chief Rajendra Kumar said.
