I am an igbo man who lost his dad a couple of yrs bak.
in my place,2nd burial is done wen d children of d dead begin to make money in order to rest d soul of d dead permanently.but smtimes wen uncles in d village bcome greedy dey begin to pour libations thereby disturbing d spirits of d dead to act negatively on d family he left behind.
His children could begin to die or his wife goes into a stroke or worse cases.
  How can we save d lives of these innocent ones who hv wronged no one but r being penalized 4 no fault of theirs but because of these greedy uncles who tend to gain 4rm d second burial.

i will give you a link, 
most  igbo people who believe in the spirit world, the Igbo's believe that a person can only reach the spirit world after a second burial,
http://www.kwenu.com/publications/iroegbu/2007/audacity_ebibi_rite.htm

;d