BANGKOK (AFP) - Thai prosecutors have dropped their case against a Hong Kong photojournalist who was arrested for carrying a bulletproof vest in his hand luggage, an official said Tuesday (March 8).

The case sparked an outcry from media freedom groups, who said Thailand should not punish reporters for carrying body armour and protective gear in and out of dangerous zones.

Anthony Kwan Hok Chun, 29, was arrested at Bangkok's Suvarnabhumi airport in August.

He had been covering the aftermath of a deadly Bangkok bomb blast at a religious shrine popular with Chinese tourists.

He was held for carrying a flak jacket and helmet in his carry-on luggage.

Both items are classified as weapons under Thai law and Kwan was charged with breaching the Arms Control Act - punishable by up to five years in jail.

"The court has made its ruling, the case is dropped," an official at Samut Prakhan provincial court told AFP. The official did not elaborate on why the case had been shelved.

Kwan, who had been released on bail, was expected to return to Thailand for the start of the trial in early April.

Media groups have criticised Thailand's classification of protective gear as weapons that require licensing, saying they are vital equipment for reporters working in a country where political violence routinely spills onto the streets.

The Foreign Correspondents' Club of Thailand, which has lobbied successive governments to overturn the ban, welcomed the decision.

"The FCCT welcomes this decision by the Thai authorities, and renews its call to them to help find a way for journalists and others, like paramedics, who need to work in dangerous areas, to be able to use appropriate protective equipment legally in Thailand," the club said.

Bangkok has long been a hub for reporters covering both the kingdom and regional neighbours, some of whom have active conflict zones.

But press freedoms have been increasingly curtailed under the Thai junta that seized power in 2014 and cracked down on criticism.

Thailand's Ministry of Foreign Affairs recently published new, stricter guidelines that have seen a number of foreign journalists denied media visas.

Most of those rejected appear to be freelance reporters, some of whom have had a presence in the country for many years.