Russian investigators are continuing a search in Sverdlovsk Oblast for an airplane that went missing on June 12 with at least six passengers.
Investigators say the flight by the An-2 aircraft was illegal because it was not sanctioned by air traffic controllers at the airport in Serov from where it took off.
Investigators say some of the passengers -- including two top-ranking local traffic police -- may have been intoxicated after drinking large amounts of alcohol before boarding the plane.
The men's cars remain parked at the airport.
No one was answering their mobile phones.
Local authorities have launched investigations into a "violation of air transportation safety regulations."
Based on reporting by Interfax and ITAR-TASS