Amnesty International has accused Tunisia's security forces of committing human rights abuses, including torture, harassment and unwarranted arrests, as they attempt to tighten security following several deadly attacks.
In a report published on Monday, the UK-based rights group said a rise in "brutal tactics" used by the security forces undermined democratic reforms in a country that was the birthplace of the Arab Spring.
The study details 23 cases of torture and other ill-treatment by police, the National Guard and counterterrorism brigades since January 2015.
It alleges that security forces have imposed abusive emergency measures which are often enforced based on appearance, religion and previous criminal convictions.
Victims recounted to Amnesty stories of torture, being "brutally beaten with sticks and rubber hoses, placed in stress positions such as the 'roast chicken' position or forced to stand for prolonged periods, subjected to electric shocks, deprived of sleep or had cold water poured on them".
One victim told Amnesty that he had been "raped with a wooden stick" in police detention.
"They beat me on my legs and feet and my arms which became bruised and inflamed. I still get nightmares from the torture I endured. They beat me until some of my toenails came off," the man, identified only as Ahmed to protect his identity, was quoted as saying.
Since the 2011 Tunisian revolution, the North African country has been hit by armed attacks that have killed more than 100 soldiers and police, some 20 civilians and also 59 foreign tourists.
Authorities have hit back by imposing a series of security measures and Tunisia has been under a continuous state of emergency since a November 2015 attack that killed 12 presidential guards.
"There is no doubt that the authorities have a duty to counter security threats and protect the population from deadly attacks, but they can do so while respecting the human rights protections set out in the Tunisian constitution and international law," said Heba Morayef, North Africa research director at Amnesty International.
Responding to Amnesty's report, Tunisian officials said they recognised that some of the Amnesty allegations existed, but added that they represented only individual cases and that there was no systematic abuse or policy of torture by state forces.
"All violations mentioned in the report Amnesty ... are individual violations (and) are being investigated. We cannot accept these kinds of violations in the new Tunisia," Mehdi Ben Gharbia, human rights minister, told the Reuters news agency.
"In Tunisia, we will win our battle against terrorism, but also will win the battle of human rights values and we will continue to reform and change in mentalities," he added.
A Truth and Dignity Commission intended to help cement Tunisia's young democracy has begun investigating police abuses and cases of torture and arbitrary arrests during decades of authoritarian rule before the 2011 revolt.