As eminent historian Andrew Roberts said when he reviewed the book in the Evening Standard last year, it manages to "brilliantly illustrate the weird, horrifying, viciously cruel place that was cold war East Germany".
It also reveals some unwittingly hilarious details - chief of which is that many former senior spies for the Stasi have flourished since the introduction of democracy by taking jobs as estate agents.
Fifteen years after the collapse of the Berlin Wall, the subject is still so sensitive to Germans today that 23 publishers in that country rejected the book before Ms Funder finally managed to have it printed there.
She said: "People were furious - they would stand up and say 'what do you know about it?'. They are trying to forget that Germany had not one but two very nasty regimes."
When she spoke to the Standard, the astonished winner had yet to text her husband Greg Allchin, who is in Sydney looking after their first child, two-year-old Imogen.
She said: "It is such a surprise. I've never won an award and I'm a very good loser."
Last night, however, she became an accomplished winner.
