Collective amnesia
Mueller depicted the exile of German Romanians in the Soviet Union in her latest novel 'Atemschaukel' from 2009.
She fled Romania for Germany in 1987, after being prohibited from publishing in her country, and it was then that she was fully discovered by the literary world.
Her major novels include 'The Passport', published in 1986 in Germany and translated in 1989, as well as 'The Appointment', translated in 2001, which describes the anxiety of a woman summoned by the Securitate.
In a 2007 article for German daily Frankfurter Rundschau, Mueller described Ceausescu, who was shot dead at the end of an uprising, as "a parvenu with water taps and gold cutlery with a real weakness for palaces."
She said Romania had developed "collective amnesia" over its repressive past.
"They're pretending that it disappeared into thin air, the whole country is afflicted by collective amnesia. Even though it was home to the most abstruse dictatorship in eastern Europe and after Stalin, the most evil dictator, with a personality cult to rival North Korea's," she wrote.
Mueller follows French author Jean-Marie Gustave Le Clezio in winning the Nobel diploma, medal and 10-million kronor (R13-million).
She is the 12th woman to win a Nobel Literature Prize. A record four women have won Nobels this year, beating the previous record of three from 2004.
After the science awards this week, the Peace Prize will be announced on Friday, and the Economics Prize will wrap up the awards on Monday.
The formal prize ceremonies in Stockholm and Oslo will be held as tradition dictates on 10 December, the anniversary of the death in 1896 of the prize's creator, Swedish industrialist and dynamite inventor Alfred Nobel.

