HONG KONG (AFP) - The sacking of a respected Hong Kong newspaper editor triggered a furious backlash from journalists and pro-democracy campaigners on Wednesday (April 20), in what was seen as the latest blow to press freedoms in the city.

Keung Kwok Yuen was fired overnight Tuesday from investigative newspaper Ming Pao, whose former chief editor was stabbed by masked attackers in the street two years ago.

Fears are growing in the semi-autonomous city that China is tightening its political grip in a number of areas, including pressurising and influencing local media.

Keung's sacking coincided with Ming Pao publishing a front-page story on Wednesday linking top Hong Kong businessmen and politicians to new revelations from the Panama Papers leak.

The trove of Panama Papers documents, released by the International Consortium of Investigative Journalists this month, has exposed how Panama law firm Mossack Fonesca helped China's rich and powerful funnel their wealth into tax havens.

Ming Pao's Wednesday front page reported that pro-Beijing actor Jackie Chan and high-profile Hong Kong politicians including Henry Tang, a former leadership candidate, have offshore accounts.

According to a statement by the Ming Pao Staff Association, Keung was fired in the early hours of Wednesday in what was billed as a streamlining exercise.

"The association is dubious over the incident, and questions the company's surface reason of saving resources," it said.

"It is penalising editorial personnel with different opinions," it said, adding that members were "extremely angry and dissatisfied".

Reporters said the decision to sack Keung was taken by Malaysian chief editor Chong Tien Siong, who is seen as pro-Beijing.

Chong was brought in two years ago to replace veteran investigative journalist Kevin Lau, triggering protests by newspaper staff.

Soon after, Lau was stabbed in the street leaving him severely wounded, sparking major concerns over reporting freedoms.

"The decision (to sack Keung) has set all the alarm bells ringing," said Emily Lau, chairwoman of Hong Kong's Democratic Party.

"The whole profession is trembling like a leaf because of political and economic pressures."

The Hong Kong Journalists Association said reporters were in shock over Keung's sacking and described the reasons as "far-fetched".

It noted that Keung played a leading role in covering politically sensitive issues such as the July 1 protest march in 2003 that drew half a million participants as well as the city-wide campaign against a national education curriculum in 2012.

“We express our utmost regret that a veteran and objective journalist like Keung ... was no longer [welcome] at Ming Pao,” the statement read.

"We are deeply worried and unsettled about the space and degree of freedom for local news," it said in a statement.

In a new report on Wednesday, campaigning NGO Reporters Without Borders said Hong Kong's press freedoms had dipped slightly in 2015 - it is now ranked 69th in the world.

Its report said Hong Kong media could still cover sensitive stories but "the need to fight to protect their editorial positions from Beijing's influence is increasingly noticeable".