You can find a reference to 'versión libre' in a human rights watch article on a Colombian law proposal,
"Human Rights Watch Recommendations With Respect To The Regulatory Decree For Law 975 Of 2005:"

"Moreover, in order to uncover all the truth about the criminal acts committed by these groups, the regulations should establish that the Attorney General’s office will interrogate each demobilized person during the ***spontaneous declaration (version libre)***, about “all the facts of which they have knowledge.”3 The interrogation should include specific questions about the assets, the financing sources, the support networks, the operations, and the structure of their group, as well as information about the individual’s date of entry in the group, pseudonyms, illegal activities, assets, and supporters."

And here it is again, in the same article:

"Article 17 of Law 975 provides that the individuals who seek benefits under the law “shall make a ***spontaneous declaration*** before the prosecutor delegate"

Note that this article is also available in Spanish.