Disclaimer: I'm not a pro-government shill. I hate everyone equally.
While the crime is very unusual, the news piece was horribly mistranslated. The five actors involved in this scandal are:
Shafik Jaraya: a destitute businessman who had big ties with the old regime. Tried to join the party that won lately but gave up. Had his glory days, but they're long gone now. His wife plays a big role in this salacious incident.
Samir Al Wafi: a corrupt journalist who used to fake articles of opposition figures and actors imprisoned for false crimes, where they "pledge allegiance" to the government, besides articles about sex frustration, how actress/singer X is good, and softcore social critique. After 2011, he said he was "too naïve", a "rookie" who "couldn't do much else", and then continued. He would then interview on Hannibal TV (a formerly pro-old regime network, now sold to Islamists with the crew flocking out like rats out of a sinking ship) some figures of corruption live (like a high executive from the ministery of interior who was accused of toture interviewed live) and then-current ruling islamist party leaders justifying themselves, as he asks "hard" questions. After 2014 or so, he switched to another highly popular TV network "Tounisia" where he has a political show with people from different political confessions being pit against each other to this very day. He refers to "Slim Jaraya" as "a figure of the old regime i still consider a dear friend since he's pious in personal life"
Wassim: a popular comedian who imitates voices of politicians from all the spectrum. Was recently (end of 2014) invited to police posts for a complaint they didn't receive, the police issued an apology, but then this happened --
Moez Ben Gharbia: an investigation reporter who started on the popular "Tounisia TV". He was ousted out of it (while the owner "Samir Wafi" was imprisoned by Islamists for one year for wanting to air something about their corruption) because he didn't comply with whatever editorial line imposed by the "frequence owner" Slim Riahi (now a politician) who was back then pro-Islamists. The network broke free from Slim Riahi by having another channel merge with them and give them their block, but Moez Ben Gharbia's refused to return - and a clone of the show he had started on Tounisia with... Samir Wafi. He hates his guts by the way for other reasons.
But I digress.
Now for the incident. According to the official piece of news, Moez Ben Gharbia and Wassim were incarcerated for "impersonating the character of the president of the republic". Also, "Samir Wafi" is also being investigated and banned from traveling outside the country. The presidence of the republic denies being the plaitiff or being against freedom of speech (and that could be a load of bullshit, or the whole case could be made up, but let's continue).
According to latest news, the lawyer of the pair (Moez Ben Gharbia, Wassim) said he can't communicate info to the public because of the sensitivity of the case, but they should be freed by monday if document gathering is done by then.
Supposedly, Shafik Jaraya is being blackmailed by Samir Wafi, who threatens to publish compromising stuff about him in 2013 (as soon as Islamists catch wind of that, he'll have to pay a loyalty tax for them or else he would rot in prison without charges until his death, as happened to other people). So he is paying him, as he insults and demeans him, regularly. Eventually, the wife is fed up and does an audio recording that incriminates Samir Wafi legally (for blackmail). He starts harassing her in turn.
She let Moez Ben Gharbia know of the whole deal, and he hates the guts of Samir Wafi and wants to start his new network with a show that would crush him. But she asks to talk with the President of Republic to make sure she and her husband will be safe, as a condition of releasing the tape. Moez Ben Gharbia calls Wassim (who imitates Sebsi quite well) and he obliges. Now impersonation is a heavy crime in Tunisia with a sentence up to 5 years. They are found out somehow (phone surveillance? a "friend" selling them out? whole story is bogus to begin with?)
And that's the story. The story is far more elaborate than a simple "lèse-majesté" crime.