Guessing starts on who among 231 nominees will win Nobel Peace Prize

Early October means it's time for the annual Nobel Prize announcements and frenzied guessing over possible winners, with 231 peace prize nominees rumoured to range from former German chancellor Helmut Kohl to burqa opponent Sima Samar and US scholar Gene Sharp.

This year, the juries are going to great lengths to keep the laureates' names under wraps in the run-up to the announcements, which start on Monday and run daily until they wind up a week later with the economics prize.

While it is usually difficult to predict who will be recognised for pioneering research in the scientific fields - medicine, physics, chemistry and economics - the public can play the guessing game when it comes to the peace and literature prizes.

The Swedish Academy, which awards the Nobel Prize for literature, is known for its cloak-and-dagger methods to prevent any leaks about its choice.

In 2005, when British playwright Harold Pinter got the nod, the members of the academy's committee referred to him as Harry Potter, whose initials he shared.

Rumours of a potential leak at the academy swirled last year, prompting anti-corruption prosecutors to investigate why betting odds on Swedish poet Tomas Transtromer went from 13-1 to less than 2-1 in the hours before the academy read out his name.

The probe was later dismissed due to lack of evidence, but the academy is taking extra precautions this year and is limiting the number of people who have access to the winner's name.