Season 1
2000 • 16 Episodes
Season 1 of Secrecy of the investigation premiered on September 1, 2000.
Season 6
2006 • 12 Episodes
Season 6 of Secrecy of the investigation premiered on December 20, 2006.
Season 10
2011 • 24 Episodes
Season 10 of Secrecy of the investigation premiered on November 9, 2011.
Season 12
2013 • 12 Episodes
Season 12 of Secrecy of the investigation premiered on February 4, 2013.
Season 13
2013 • 20 Episodes
Season 13 of Secrecy of the investigation premiered on December 16, 2013.
Season 14
2014 • 16 Episodes
Season 14 of Secrecy of the investigation premiered on December 15, 2014.
Season 15
2015 • 16 Episodes
Season 15 of Secrecy of the investigation premiered on December 14, 2015.
Season 16
2016 • 20 Episodes
Season 16 of Secrecy of the investigation premiered on December 5, 2016.
Season 17
2017 • 24 Episodes
Season 17 of Secrecy of the investigation premiered on December 11, 2017.
Season 18
2018 • 24 Episodes
Season 18 of Secrecy of the investigation premiered on December 17, 2018.
Season 19
2019 • 24 Episodes
Season 19 of Secrecy of the investigation premiered on December 9, 2019.
Season 20
2020 • 24 Episodes
Season 20 of Secrecy of the investigation premiered on December 14, 2020.
Season 21
2021 • 24 Episodes
Season 21 of Secrecy of the investigation premiered on December 13, 2021.
Season 22
2022 • 18 Episodes
Season 22 of Secrecy of the investigation premiered on December 5, 2022.
Season 23
2023 • 16 Episodes
Season 23 of Secrecy of the investigation premiered on December 7, 2023.