Baduel, a retired general, was convicted in 2010 to nearly eight years in prison for embezzlement and abuse of power for alleged crimes dating from his time as defence minister in 2006-2007.
But Baduel, in an exclusive interview from his prison cell in Ramo Verde outside the capital Caracas, told AFP he had been the victim of political persecution since he left Chavez's government.
"In 1982, I swore with Chavez to work tirelessly for a true democracy. But he decided to forget that pledge and instead pursue efforts to remain president for life in a Venezuela in shambles," Baduel said.
The two men were once close. They met nearly 40 years ago at the country's prestigious military academy, where they promised each other to "work together for the creation of a better democracy," according to Baduel.
The former general joined Chavez in government when he took power in 1999. In April 2002, Baduel led the operation that allowed the leftist firebrand to remain in power following a coup attempt.
But their relationship later soured, and they severed all ties in 2007, when Baduel campaigned against Chavez's proposals for a new Socialist constitution, which was eventually rejected in a referendum.
"In April 2002, I fulfilled my duties and remained faithful to the constitution. In 2007, I once again felt the need to say I thought things had taken a turn for the worse," Baduel told AFP.
After leaving government, the former minister was accused of corruption and then sentenced in May 2010 to seven years and 11 months in prison. He says proper legal procedures were ignored and the charges never explained.
"They could not even agree on the amount that I had supposedly embezzled," said the 56-year-old Baduel, his cell decorated with religious images and photos of South African anti-apartheid icon Nelson Mandela.
"I could have fled, but I decided to stay because I know I am innocent. They accuse me of being a traitor. Traitor to what? To whom? To one man? I prefer that than to betray millions of people," he added.
"Today, I think the man I once knew lied to me. I think that Chavez has always had a hidden agenda," Baduel said, calling his former friend's government a "dictatorship in disguise" coloured by a "cult of personality".
He urged the people of Venezuela to rally, likening the atmosphere in the country to a "pressure-cooker without a steam release valve".
Baduel nevertheless acknowledged that the country's problems would not disappear with the departure of Chavez, who is now battling cancer.
One year ahead of expected presidential polls, the general said he had not ruled out the possibility of being granted amnesty, as Chavez -- who will be seeking a third term -- could possibly see it as politically advantageous.
As for his onetime friend's health problems, Baduel said: "He was forced to submit himself to God's power, and God reminded him what life is worth."
Copyright AFP (Agence France-Presse), 2011