The suicide note left by a retired Army general who took his life on Friday has been disclosed.

Lee Jae-su, former chief of the now-disbanded Defense Security Command, jumped to his death after being questioned over alleged abuse of his authority to investigate families of victims of the 2014 Sewol ferry sinking.

According to his lawyer, in the note he left behind, Lee expressed regret over the ongoing probe related to an incident from five years ago.

Lee said the Defense Security Command and its staff were devoted and did their best at the time of the Sewol ferry disaster. 

He said he lived a blameless life but was caught up in a complicated political situation since retiring from the post. 

He apologized for causing trouble to many people, adding that he has been pushing for many business projects ambitiously as of late.

He also asked prosecutors to be generous to others involved and that he will take the blame. 

Lee headed the DSC for one year from October 2013. He has been grilled by prosecutors on charges of ordering illegal surveillance of the bereaved families of the Sewol victims in 2014 ahead of provincial elections. 

Early this month, the prosecution sought an arrest warrant for Lee but the court dismissed the request saying he posed no risk of flight or evidence destruction.