One year after a prominent Iraqi journalist and government critic was killed, no one has been arrested for his murder and activists and analysts say press freedoms have, if anything, worsened.

Hadi al-Mehdi died of a single gunshot wound to the head on September 8, 2011, a day before planned nationwide rallies he was involved in organising against poor basic services and rampant corruption.

Many blamed the authorities for Mehdi's death -- a charge officials denied, pledging a special investigation.

But as the months passed no arrest has been made, and no inquiry results have been made public.

Mehdi's friends and supporters insist he has not been forgotten, with the radio station he worked at planning a special day of programming, and journalists and activists organising events and demonstrations in his memory this week.

"Hadi would say what people wanted to say but couldn't -- they didn't have his courage," said Karnas Ali, technical director at the Demozy radio station where Mehdi broadcast three 90-minute shows a week.

"His programme was the kind of work that makes enemies," Ali said.

"Whenever I read his comments, I would tell him he was writing a suicide note."

Mehdi's radio show, Ya Sameen al-Saut ("You, Who Can Hear This Voice"), was known for its sharp criticisms of official incompetence and corruption.

He was also a playwright, wrote for several publications and helped organise regular anti-government demonstrations.

At the biggest of those rallies in February 2011, Mehdi was among four Iraqi journalists detained by security forces, and alleged they subjected him to electrical shock treatment and repeated insults during interrogation.

His murder sparked a public outcry, drawing condemnation from rights groups and spurring dozens to the streets for his funeral, a march through central Baghdad carrying an empty coffin draped in an Iraqi flag.

Authorities have not published any findings from the promised inquiry, or announced any arrests. Deputy Interior Minister Adnan al-Assadi declined to comment to AFP on the case.

"They are trying to catch air with a net," said Muayad al-Tayyib, using an Arabic phrase to allude to criticism that officials have not genuinely tried to find any of those responsible. Muayad, a 30-year-old journalist and friend of Mehdi, was among those who carried his "coffin" a year ago.

Rights groups and diplomats point to Mehdi's death, and the subsequent apparent lack of a comprehensive investigation, as one of many problems affecting journalism.

"Day by day, press freedom in Iraq is shrinking," said Ziad al-Ajili, head of the Journalistic Freedoms Observatory, an Iraqi watchdog. "Those who say there is freedom of the press should talk to journalists on the ground."

Iraq ranks atop the New York-based Committee to Protect Journalists' Impunity Index, with the CPJ saying there have been no convictions for the murders of journalists since 2003, when Saddam Hussein was ousted by a US-led invasion.

A bevy of new laws and bills also threatens to limit freedom of expression.

Along with what has been described by activists as a flawed Journalists Protection Law, currently being challenged in court by local rights groups, bills on Internet security, freedom of expression and political party organisation are being considered.

These include vague and poorly defined terminology, such as violating "public morals" or conveying "immoral messages," along with what analysts and diplomats call disproportionately harsh punishments.

"The combination of vague terms and extreme punishments outlined in these draft laws could have a chilling effect on freedom of expression in Iraq," one Western diplomat said, speaking on condition of anonymity.

But Prime Minister Nuri al-Maliki's spokesman Ali Mussawi has insisted that Iraqi journalists now "enjoy huge freedoms."

"Developments in the media, in all its forms, represent tremendous progress, and cannot be compared to the time of the former regime," Mussawi said of Saddam's rule.

In the year since Mehdi's death, Demozy has scaled back its coverage of politics and corruption because, as Ali noted, "we couldn't find a replacement for Hadi. We tried, and we are still trying."

The station suspended regular programming for two weeks after Mehdi's murder, instead airing passages from the Koran interspersed with condolences and discussions with his friends and other officials.

Ali and Tayyib both pointed to the fact that Mehdi had relatives in Denmark as proof that he could have left the country, but chose to stay.

"We lost a brave journalist, and me, I lost a friend, an educated man, a funny man with a big heart," said Ali.

"He came to a homeland lacking in services, lacking in respect for its citizens," he added. "He was a patriot."