I thought there was a whole module in junior espion class on not using the home office as your "In case of Emergency, Call" number.
Lifted in toto from the AP via ABC (US) News:
Two journalists say the passport file of one of the suspects in the poisoning of a Russian former double agent and his daughter in England contains a telephone number that appears to belong to Russia's Defense Ministry.Belligcat, an online investigative organization headquartered in England, published a phone number Friday that it said came from what it described as the passport records of Alexander Petrov, one of the two men British authorities charged in the poisonings and alleged were Russian military intelligence agents.The number does not bear a city code. Oliver Carroll of British newspaper The Independent and Patrick Reevell of ABC News tweeted they called it using a Moscow prefix and the person who answered said they'd reached a Defense Ministry number.Calls to the number from The Associated Press were not answered Saturday.
From what I understand, Bellingcat is a bit sketchy.
