Rwanda Defence Force (RDF) said Thursday military prosecution will arraign Colonel Tom Byabagamba before military courts for additional charges committed while in detention.
Byabagamba is suspected of committing more criminal activities related to attempting to commit corruption and attempting to escape from prison.
"Suspected criminal activities committed by Colonel Tom Byabagamba and his inside and outside accomplices are being thoroughly investigated," RDF said in a statement.
The statement did not divulge further details of how he intended to escape prison.
A former commander of the Republican Guard, Byabagamba was arrested on August 24, 2014 and in 2016, he was sentenced to 21 years in prison by the Military High Court.
Last year in December, the Court of Appeal reduced his sentence to 15 years and stripped him off his military ranks.
He was found guilty of inciting insurrection or trouble amongst the population, and tarnishing the image of the country or Government.
Byabagamba was also found guilty of wilfully concealing objects that would facilitate the execution of a crime, and contempt of the national flag.
"The RDF reassures the public that justice will take its course and will not tolerate any person who violates the law and RDF ethics and values," the statement reads in part.