The number of people who have stayed beyond their legal visits has been on a continuous increase in South Korea, with the visa-free Jeju Island in particular feared to become the hotbed for such visa violations.

The increase has naturally led to a jump in illegal entry and employment.

According to the Justice Ministry, the number of so-called overstayers in the country has shown a surging trend in recent years -- 167,780 in 2011, 177,854 in 2012, 183,106 in 2013, 208,778 in 2014 and 214,187 last year.

The 2015 figure is more than three times higher than that of Japan, which recorded a relatively humble 62,818 on account of effective strict crackdowns.

In 2004, Japan launched a five-year program to halve the number of foreigners who overstay their visas, with major steps including a sharp increase of crackdown workforce and fines on employers who hire them. It even revokes the business licenses of violating employers.

South Korea adopted a similar program this year with the goal to bring down the number of immigrants who overstay their visas to below-200,000. But the goal does not seem achievable in the near future due largely to low manpower. 

According to the ministry, the number of officials in charge of finding overstayers nationwide is only about 150 per immigration office, which means one agent has to track down more than 1,400 people living in the country illegally.

Jeju, one of the country's most popular tourist sites, has seen the biggest increase in the number of visa overstayers in recent years.

The population of foreign visitors there rose from 1,045,673 in 2011 to 1,681,399 in 2012, 1,812,172 in 2013, 2,859,092 in 2014 and 1,624,260 in 2015.

In the 2015 figure, Chinese visitors accounted for a whopping 85.3 percent.

The number of foreigners who visited Jeju without a visa also soared from 113,825 in 2011 to 232,929 in 2012, 429,221 in 2013 and 645,301 in 2014 and slightly declined to 629,724 last year decisively on account of the Middle East Respiratory Syndrome (MERS) outbreak that hit the nation, killing 36 people.

The growth in the number of visa overstayers is noticeable especially since 2013 when the number of foreigners visiting the island crossed the 2-million line.

A Jeju government official said the rapid jump stems from the increase of overseas and local brokers who help these foreigners illegally find jobs. The spread of information on the island's favorable economic conditions among Asian nations was also a major contributing factor.

 In particular, the visa-free system, which the island introduced in 2008 to attract more Chinese tourists is being abused as a channel for illegal entry and employment.

Under the Special Act on the Establishment of Jeju Special Self-Governing Province and the Development of a Free International City, all tourists except for nationals from 11 terror-sponsoring countries can enter and stay on the island without a visa for up to

30 days.

On the other hand, the average arrest rate for those who overstay on Jeju remained at 29 percent from 2011-2014, with 53 cases in 2011, 147 in 147 in 2012, 172 in 2013 and 602 in 2014.

An example of the misuse of the visa-free program happened on Jan. 13, when 59 of 155 Vietnamese tourists on a group tour to Jeju with no visas disappeared from their lodging. There are 23 fugitives still at large.

Such lag capturing people who violate their visas is ascribable to the shortage of crackdown officials and ever-evolving tricks for illegal entry.           

In November 2012, the coast guard arrested two Chinese nationals and a broker who attempted to enter the mainland from Jeju by using a small boat. The broker unsuccessfully tried to hand them over to a fishing vessel off the coast of the island after departing a Jeju port aboard a small boat.

A Chinese man was caught while trying to take a Jeju-Wando ferry by hiding in a van in March last year, and seven Chinese people and their local broker were nabbed at Jeju's Hanlim Port while trying to secretly leave the island hidden in a container carried on a freighter.

It is not rare for overstayers to be caught while illegally working on the island as well.

On April 26, four brokers were prosecuted on charges of helping immigrants find illegal jobs at farms, factories and construction sites on the island. In a probe into the brokers, 26 Chinese men were deported after being arrested on the scene and 21 employers were found to have illegally hired immigrants in a bid to lower their wage burden.

However, no employer who had hired such workers has been taken into custody thus far, inviting criticism that such leniency foster the spread of illegal employment.

Notable is the fact that the number of foreign brokers is also on the rise.

There are an increasing number of cases where Chinese and Chinese-Korean brokers take foreigners from the island in collusion with local counterparts, and arrange jobs for them in other regions of the country.

According to the police, some foreigners who enter the country illegally or overstay visas intentionally come to Jeju initially, with the intent to find jobs in other areas, as the island is a relatively easy channel for entry.

The increase of those who overstay visas on the island has resulted in the increase of crimes committed by foreigners there.

According to the Jeju prosecution office, the number of foreign offenders surged from 350 in 2011 to 335 in 2012, 457 in 2013, 477 in 2014 and 673 in 2015.

Crime is also becoming more violent, with an increase in robbery, drugs, sexual harassment, rape and homicide.

In June last year, a 23-year-old Chinese man who overstayed his visa stabbed his compatriot with a knife at a night club.

In April, a 30-year-old Chinese national was arrested on charges of confining and attacking a 44-year-old Chinese realtor to extort money.

On April 7, a Chinese man in his 50s attempted to rape a housewife after breaking into her house.

There was also one homicide reported every year from 2011 to 2015.

Officials from the police, prosecution and immigration office on Jeju strongly voice the need for supplementary guidelines to the visa-free system as soon as possible.

In a recent briefing on foreigners in the country illegally, Kim Han-soo, a senior prosecutor at the Jeju Prosecutors' Office, warned that Jeju could be full of such immigrants because of their misuse of the visa-free system.     

"We'll stage stern crackdowns on those who overstay their visas, illegal brokers and illegal employers to root out their wrongdoings," Kim said. (Yonhap)