Attempts to extradite ex-intelligence technician Edward Snowden, charged with espionage by US authorities, will result in a protracted legal battle in Hong Kong that could last years, experts said Saturday.

Hong Kong, a former British colony that retained a separate legal system when it returned to Chinese rule in 1997, has a long-standing extradition treaty with the US, but Beijing has the potential to veto any ruling.

However Beijing has appeared to distance itself from any decision on the possible extradition of Snowden, who is in hiding in the southern Chinese city after blowing the lid on vast US surveillance programmes targetting phone calls and Internet traffic.

Hong Kong officials remained tight-lipped on Saturday as to whether they will hold Snowden a day after Washington charged the former CIA contractor with espionage, theft and "conversion of government property".

Hong Kong lawmaker Alan Leong said that if local authorities proceed with extradition, it could result in a lengthy legal battle.

"If every appeal opportunity is taken, I suppose the process will last between three and five years" at the very least, he told AFP.

The case could possibly drag "through at least the magistrates' court, the Court of Appeal and the Court of Final Appeal. So, at least three levels of (Hong Kong) courts," he said.

Snowden can claim fears of political persecution and ask for political asylum, which will buy him time, said Christopher Gane, the dean of law school of Chinese University of Hong Kong.

"If the court decides this man cannot be sent back, this is the end of it. He can't be sent back," he told AFP.

"But if the court decides he could be sent back, it is still up to the Hong Kong chief executive to decide whether to do so. This is when all kinds of possible considerations can come in," Gane said.

Experts have claimed that Snowden is testing Hong Kong's civil liberties under its "one country, two systems" framework by retreating to the former British colony.

Snowden has exposed details on vast US surveillance operations, leaking documents that appear to show huge quantities of private telephone and Internet data -- such as emails and call records -- have been scooped up with little or no judicial oversight.

The revelations have embarrassed US President Barack Obama's administration, which was forced to defend US intelligence agencies practice of gathering huge amounts of telephone and Internet data from private users around the world.

Snowden has warned more leaks were on the way, declaring: "Truth is coming and it cannot be stopped."

WikiLeaks plane 'ready' to bring Snowden to Iceland
Reykjavik (AFP) June 21, 2013 - A chartered private jet is ready to bring US intelligence leaker Edward Snowden to Iceland from Hong Kong, a businessman connected to whistleblowing website WikiLeaks said late Thursday.

"Everything is ready on our side and the plane could take off tomorrow," Icelandic businessman Olafur Sigurvinsson, head of WikiLeaks partner firm DataCell, told Channel2 television.

"We have really done all we can do. We have a plane and all the logistics in place. Now we are only awaiting a response from the (Icelandic) government," added the boss of Datacell, which handles donations to WikiLeaks.

The private jet belongs to a Chinese firm and has been chartered at a cost of more than $240,000 thanks to individual contributions received by Datacell, he said.

WikiLeaks founder Julian Assange said Wednesday he had been in contact with representatives of Snowden to discuss his possible bid for asylum in Iceland following his disclosure of US surveillance programmes.

Former US government contractor Snowden, who turns 30 on Friday, fled to Hong Kong on May 20. The United States has yet to file any formal extradition request after his bombshell leak of the National Security Agency programmes.

Iceland has said it held informal talks with an intermediary of Snowden over the possibility of seeking political asylum, but that he must present himself on Icelandic soil.

Snowden has expressed an interest in taking refuge in Iceland, saying it is a country that stands up for Internet freedoms.

However, observers say Iceland's new centre-right coalition may be less willing to anger the United States than its leftist predecessor.

Interior Minister Hanna Kristjansdottir said Tuesday that the government did not feel bound by a 2010 resolution by parliament seeking to make the country a safe haven for journalists and whistleblowers from around the globe.

"The resolution is not a part of the laws that apply to asylum seekers," she told public broadcaster RUV.

Sigurvinsson said it was unlikely that Snowden would travel to Iceland without receiving a green light from the government in Reykjavik.

"It would be stupid to come here only to be extradited to the United States. In that case he'd be better off where he is," the businessman said.

Snowden has gone to ground in Hong Kong, surfacing to conduct media interviews from undisclosed locations.

Assange this week marked a year in refuge at the Ecuadoran embassy in London. Sweden wants to put him on trial for rape, but the WikiLeaks founder says the prosecution is politically motivated.