Here is some further info on losing your passport in Moscow.
In Russia, the loss of a passport is a serious matter. Without a passport, a traveler can face significant difficulties with hotels, banks and the police. In addition, you must replace your Russian visa as soon as your receive your new passport.
If you lose a passport while in Russia, you must do the following:
* Report you passport lost or stolen to the Russian police. You will need a police report to carry with you until you replace the passport and visa.
* Report the loss to the U.S. Embassy or nearest Consulate General.
* Complete the Statement Regarding a Lost or Stolen Passport and submit it with your application for a new passport, together with Application Form DS-11, fees, and passport photos. In addition, please bring the police report and any photo identification.
* In the case of a child's lost passport, both parents must appear with the child. Please see our section on Passports for Minors.
* Once you have your new passport, you will need to apply for a new Russian visa.