Reporters Sans Frontieres has written to the government and the independent television commission to complain about what it describes as the "harassment" of a UK-based TV station by the Tunisian government.
RSF, which acts to protect the freedom of journalists globally, has accused the Tunisian authorities of orchestrating a "smear campaign" against the broadcaster, which is critical of the government.
Robert Menard, the secretary general of the organisation, has written to the Foreign Office urging it to contact its Tunisian counterparts and make them aware of its concerns.
"We are deeply concerned about a smear campaign orchestrated by the Tunisian government against the London-based Arabic TV channel, Al Mustakillah, and its founder and director Mohammed Elhachmi Hamdi," says M Menard in the letter.
"Since spring 2001, many of his family members who still live in Tunisia have been intimidated," M Menard continues.
"At the same time, Mohammed Elhachmi Hamdi has been the victim of a smear campaign perpetrated by several Tunisian media, close to the regime, in which he has been branded as a 'terrorist', a 'traitor', a 'British agent', an 'Israeli agent' or an 'agent of European colonialism'."
Mr Hamdi told MediaGuardian.co.uk that for months the information minister has criticised his policy of giving airtime to dissidents critical of the regime.
He claimed the government had called on the holy men of North Africa to issue a fatwa against him, and cited Tunisian newspaper reports that he claimed were evidence of a government propaganda campaign against him.
"I have been attacked as a traitor because I am broadcasting in French," said Mr Hamdi, "because they say it is the language of the colonial oppressors."
"I was told the president of Tunisia was very unhappy. I have since received an open letter denouncing me as a terrorist, a traitor to Arab nationalists and a Zionist."
Mr Hamdi also claimed members of his family still living in Tunisia had been forced by state officials to speak out against him.
"They went to my family and told them the governor of the province and chief of police would ask them to sign a statement publicly renouncing my actions," he said.
"In an Arabic newspaper on January 16 I found a statement signed by my family, expressing their total condemnation of what I had said."
The government had objected to two weekly programmes on Tunisian politics, Le Grand Maghreb and L'Espace Francophone.
It was also angered by the channel's invitation to dissidents of the regime, in particular Mr Menard, chief executive of Reporters Sans Frontieres, and the spokeswoman for the Tunisian National Council, Sihen Ben Sedrine, both of whom have criticised the government's record on human rights.
"Most Arab governments have accepted that there is a need for openess and impartiality in the media," said Mr Hamdi.
A spokesman for the Tunisian embassy said the embassy was not yet aware of the specifics of the letter, but said Mr Hamdi had a "hidden agenda".
"We are not aware of any harassment against Mr Hamdi," he said. "He is a member of a terrorist group who has been condemned by a Tunisian court. He has got a hidden agenda."
The ITC confirmed that it had received a number of complaints about Al Mustakilla, but would not be drawn on the details.