I will repost your query on the boards where historians and history teachers from Serbia hang out.  Based on military records your ancestor may have been initially presumed dead as he was MIA, and the later  additional note may have been the result of military authorities receiving new information about him - there should be a paper trail and you need to examine the full archival holdings from his army unit/command -all memos and correspondence.

As for the Military Archive in Belgrade - I have not contacted them personally yet but will make a few calls and see if I can find out that way about which records exist and where. If that yields no results, you may have to fill out an official request for information and pay them a fee for that to get their official reply.

I am re-contacting the Czech Military Museum which supplied me the registers about my grandfather. I am asking them if they have more papers concerning this subject. Thank you also for calling the Serbian Military Musem.

You are welcome. I briefly browsed some historical accounts and sources in Serbian language and in some of them the Czech batallion (referred to as VIII or *Prague batallion also) is noted with many soldiers who did surrender immediatelly after the counter-offensive of the Serbian forces began.

 

Also you need to have the dates and battles clarified if possible by the archive in your country - the Kolubara battle  lasted officially  30 days from 16.11. 1914 - 15.12. 1914.

 

If you are going to google/search academic databases for results in Serbian language use these keywords:

Kolubarska bitka, prvi svetski rat, austrougarska vojska, zarobljenici.

With Czech and Serbian being Slavic languages,  I am pretty sure that you will be able to navigate any  content  written in Serbian language  with the help of a good online dictionary.

-Here is a link to a military forum ( in Serbian) where people posted detailed maps and citations from historical documents:

http://www.mycity-military.com/Prvi-svetski-rat/Kolubarska-Bitka-2.html

-Here you will find a scan of the Kolubara battle edition of a military magazine. On page 9 there is a photo titled *Zarobljeni austrougarski vojnici*  - captured soldiers of Austria-Hungary army. The number of these captured soldiers in that battle alone was over 40.000.

http://www.scribd.com/doc/39233117/Kolubarska-bitka

- this next link is to a  a photo  titled " Princ Aleksandar Karadjordjević razgovara sa Austrougarskim ratnim zarobljenicima,septembar 1915" - prince Aleksandar Karađorđević talking to Austro-Hungarian POWs in September 1915 -

 

-Here is a documentary from Serbian state TV about the battle with many original films and photos :

http://www.youtube.com/watch?v=Nc2JRA-_Ol4

I know that it may be intimidating to you to go through all of these as the perspective is that of the country and the army that your ancestor fought against, but I have no non-Serbian sources that cover the subject of this batlle to recommend which have that much original or detailed information on the batlle itself.

- a book was published in Serbian language titled "Austro-Hungarian POWs in Serbia 1914-1915". You may want to get hold of it either through online library catalogues or through the central National Library in Belgrade which has copies of all published books in Serbia:

author: Isidor Đuković

title: "Austrougarski zarobljenici u Srbiji 1914-1915”

published about four or five years ago.

http://books.google.hu/books/about/Austrougarski_zarobljenici_u_Srbiji.html?id=RVD1pwAACAAJ&redir_esc=y

 

Dear yugaya,

 

Many thanks for the very useful links. I am presently "digesting" all the information. The key words you suggested to me opened new research paths.

All the best,