TUNIS (Reuters) - A Tunisian journalist whose six-month jail sentence for assault was condemned by international rights groups said after his release on Tuesday he was unbowed and would write a book about his experiences.

Taoufik Ben Brik was found guilty of attacking a woman motorist during an argument in the street. He and his supporters said the charges were concocted to punish him for his criticism of Tunisian President Zine al-Abidine Ben Ali.

"I will stay true to my courage," Ben Brik told Reuters in a telephone interview soon after he was released on completion of his sentence. "In the coming days I will start writing a book about this miserable story."

Ben Brik's case focused international scrutiny on human rights in Tunisia, a mainly Muslim country in North Africa that has been dominated by 73-year-old Ben Ali since he came to power 23 years ago.

Tunisian authorities deny any political motive behind Ben Brik's prosecution. Officials said assault on a woman was a serious offence and no one should be above the law.

The journalist said his experience in prison, where his relatives said he became dangerously ill, would leave a permanent mark on him.

"The damage has been done, and this damage will always cause me fear," he said from his home in the Tunisian capital. "Even though I am free, I never feel safe here."

Ben Brik said he would be soon be travelling to Paris, though he denied he would be leaving Tunisia permanently. He said France was "the only country that defended me", referring to the French government's criticism of his jail term.

Tunisia is particularly sensitive to European criticism because it is preparing to apply to the European Union for "advanced status," which could give it preferential trade terms.

Tunisia's economy is one of the most open in the region and it depends on tourists, including many from the EU, and growing investments from European firms.

Freedom of speech campaign group Reporters Without Borders (RSF) said in a statement it was relieved Ben Brik had been released and was back with his family.

"However, we repeat that these six months of detention were six months too long, since it is clear that Taoufik was the victim of a case that was made up from start to finish," RSF Secretary-General Jean-Francois Julliard said in the statement.