All of the boys and their 25-year-old coach, who make up the 'Wild Boars' soccer team, will be discharged from hospital next week following a three-day rescue that evoked international relief and joy.

Although the Wild Boars are now viewed in this Southeast Asian country as national treasures, four of them are technically stateless. At least two of the boys, however, are already in the advance stages of obtaining citizenship.

"I feel very good that the Wild Boars cave story has put a spotlight on this issue," Tuanjai Deetes, Commissioner of the National Human Rights Commission of Thailand, told Reuters.

"We must put more emphasis on this domestically as well as internationally. There are still many stateless people."

According to official statistics, 486,440 people are registered with the Thai government as stateless, of whom 146,269 are - like three of the Wild Boars - under 18 years old.

There are several groups whose people have over generations moved around the region, across open borders in remote hills between southern China, Myanmar and Laos, and into northern Thailand's ethnic patchwork of communities.

The blurry-border province of Chiang Rai, at the northern tip of Thailand, has long been an entry point for illegal migrants, people smuggling and drug trafficking from the 'Golden Triangle' area that straddles Thailand, Myanmar and Laos.

But it is the better economic conditions in wealthier Thailand that have most attracted families from the other side of the border.

Once in Thailand, they are eligible for basic education and healthcare but face travel restrictions, have no access to financial services, and cannot get married or buy property.

"Whilst some progress has been made, stateless people in Thailand continue to face challenges accessing some of their basic rights," said Hannah Macdonald with the United Nations High Commissioner for Refugees (UNHCR).

"Examples include restrictions on their freedom of movement, healthcare, access to financial services, being able to get married, and to own property or land."

Somsak Kanakham, chief of the district office in Mae Sai, the area within which the boys were trapped in the cave, said his office was ultimately just following Thai law.

"I understand why on human rights grounds we all want to resolve this issue," he said. "But it's a matter which concerns national security."

'MAJOR CHALLENGE'

The number of people in limbo is understated by the official data because many have not yet registered as stateless.

In the Mae Sai district alone, there are more than 27,000 pending cases of stateless people who have applied for Thai citizenship.

"The last time the government surveyed this village was in 2011. Now there are more than 210 new people," Tuanjai told Reuters in the village of Prachao Tum Jai, 8 km (5 miles) from the cave, where around 400 people of the "Dara-ang" hill tribe live.

Most of the villagers, who make a living by growing pineapples and rice, do not have Thai citizenship, and over 200 are not even registered as stateless, Tuanjai said.

"The major challenge is the migration pattern. There is a lot of movement, and a lack of information about the registration process."

Stateless people who can prove they have lived in Thailand for at least 10 years can apply for citizenship, which then takes around six months to process, said Vitat Techabun, director-general of Thailand's Department of Children and Youth.

But Tuanjai says "exploitation by officials" who demand bribes to facilitate citizenship applications has sometimes stood in the way of this process.

Mae Sai district chief Somsak Kanakham said his office has partnered with civil society groups on the issue to ensure more transparency and combat corruption.

The Wild Boars' coach, 25-year-old Ekkapol Chantawong, is a member of the Tai Lue minority, one of several groups in the region. He hopes to become a Thai citizen, a friend and relative told Reuters last Thursday.

Tarn Aree, 35, another stateless Tai Lue who lives in the town of Chiang Rai, and her son are struggling to obtain citizenship. Despite her son's age, 11, he has the same technical status as a "migrant worker", meaning he is officially living in Thailand, the country of his birth, temporarily.

"Many of us have been applying for citizenship for years but we haven't got it," said Tarn as she queued with friends for free bags of rice at a fair hosted by a Buddhist temple.

"We can't technically buy land so we need to use other people with Thai citizenship to buy land for us," she said. "I just want my son to truly own our home".