Season 1 of Secrecy of the investigation premiered on September 1, 2000.

Season 2 of Secrecy of the investigation premiered on March 5, 2003.

Season 3 of Secrecy of the investigation premiered on March 1, 2004.

Season 4 of Secrecy of the investigation premiered on March 14, 2005.

Season 5 of Secrecy of the investigation premiered on April 24, 2006.

Season 6 of Secrecy of the investigation premiered on December 20, 2006.

Season 7 of Secrecy of the investigation premiered on March 26, 2008.

Season 8 of Secrecy of the investigation premiered on April 16, 2009.

Season 9 of Secrecy of the investigation premiered on October 24, 2011.

Season 10 of Secrecy of the investigation premiered on November 9, 2011.

Season 11 of Secrecy of the investigation premiered on May 2, 2012.

Season 12 of Secrecy of the investigation premiered on February 4, 2013.

Season 13 of Secrecy of the investigation premiered on December 16, 2013.

Season 14 of Secrecy of the investigation premiered on December 15, 2014.

Season 15 of Secrecy of the investigation premiered on December 14, 2015.

Season 16 of Secrecy of the investigation premiered on December 5, 2016.

Season 17 of Secrecy of the investigation premiered on December 11, 2017.

Season 18 of Secrecy of the investigation premiered on December 17, 2018.

Season 19 of Secrecy of the investigation premiered on December 9, 2019.

Season 20 of Secrecy of the investigation premiered on December 14, 2020.

Season 21 of Secrecy of the investigation premiered on December 13, 2021.

Season 22 of Secrecy of the investigation premiered on December 5, 2022.

Season 23 of Secrecy of the investigation premiered on December 7, 2023.