Complex sentence: In March 2009, the magazine "CartaCapital" published previously unreleased documents of the National Intelligence Service created by an undercover agent on Jango's properties in Uruguay, which reinforces the theory that the former president was poisoned.
Split into simpler sentences: In March 2009, the magazine "CartaCapital" published previously unreleased documents of the National Intelligence Service created by an undercover agent who was present at Jango's properties in Uruguay. This revelation reinforces the theory that the former president was poisoned.