▁have ▁in fil tr ated ▁the ▁president ' s ▁security ▁detail . ▁ ▁The ▁most ▁serious ▁case ▁of ▁intelligence ▁ag ency ▁wrong do ing ▁involved ▁bank er ▁Os val do ▁S iv ak . ▁S iv ak ▁had ▁been ▁kid n apped ▁for ▁r ans om ▁by ▁Battalion ▁ 6 0 1 ▁agents ▁in ▁ 1 9 7 9 , ▁and ▁again ▁in ▁ 1 9 8 5 ; ▁his ▁buried ▁cor pse ▁was ▁found ▁two ▁years ▁later . ▁ ▁A ▁subsequent ▁investigation ▁by ▁Federal ▁Police ▁Chief ▁Juan ▁Áng el ▁Pir ker ▁revealed ▁that ▁S iv ak ▁had ▁been ▁kid n apped ▁and ▁murder ed ▁by ▁former ▁Federal ▁Police ▁capt ains ▁who ▁had ▁worked ▁for ▁both ▁Battalion ▁ 6 0 1 ▁and ▁S IDE ▁during ▁the ▁dict ator ship . ▁Because ▁S iv ak ▁was ▁a ▁top ▁fund ra iser ▁and ▁close ▁personal ▁friend ▁of ▁President ▁Alf ons ín , ▁the ▁murder ▁was ▁interpreted ▁as ▁a ▁threat ▁against ▁Alf ons ín ▁and ▁his ▁efforts ▁to ▁reform ▁the ▁two ▁ag encies . ▁The ▁" Capt ains ' ▁Band ," ▁as ▁it ▁became ▁known , ▁was ▁responsible ▁for ▁numerous ▁other ▁high - profile ▁r ans om ▁kid n app ings ▁from ▁ 1 9 7 8 ▁to ▁ 1 9 9 1 , ▁including ▁those ▁of ▁Kar ina ▁W ert hein ▁and ▁Maur icio ▁Mac ri . ▁Like ▁their ▁military ▁and ▁police ▁counter parts , ▁intelligence ▁officers ▁imp licated ▁in ▁the ▁D irty ▁War ▁benef ited ▁from ▁Full ▁Stop ▁and ▁Due ▁O bed ience ▁laws