Ludek Pachman - history question

I am reading one of Mr. Pachman's books and decided to google him (I'm new to chess... really).  And I found out that he was tortured after Czechloslovakia was invaded by Russia.  What, if any, are the details about why and who? (Please, leave what happened to be forgotten, I don't want gore.) But why and who?  I read something about a cellar.  Anyone here know more?

http://www.chesshistory.com/winter/extra/pachman.html

Bumping it up in case anyone know.

Google is your friend.

There is a little bit of detail in this NY Times obituary. Here is the UK Independent's obituary (I wonder what Kasparov would think of the opening sentence?). Chessbase obituary.

I did do some googling and sadly its very sketchy.  Sometimes the details of these sort of governmental atrocities are lost to history.  I suspect it was just part of general mistreatment b/c of his Czech Nationalism.  Not to mention the ideology of communist vs non-communist was even considered a moral issue by the planet at that time.  I was thinking he was involved in some plot or something but it sounds like the real reasons have been lost to time or only Mr. Pachman and his tormetors know what the reasons were.

I read that he actually attempted suicide during his imprisonment.

Yes, by jumping off something and trying to brain himself. The net result was a painful neck injury that he suffered from for the rest of his life.

His books are instructional classics. I'd recommend them to anyone who wants to improve.