SEOUL • Mr Shim Goo Seob has been organising private, high-risk reunions for North and South Korean families for more than two decades, but now he is close to calling time on his secretive work.
Tighter border security and soaring costs have seen the number of such reunions plunge from a high of nearly 300 in 2003 to just 10 last year - and none so far this year.
"Border crossings have become far more dangerous and expensive. Our operations have basically come to a standstill," Mr Shim said.
Millions of families were split up by the 1950-53 Korean War which cemented the division of the Korean peninsula into North and South. Most died without ever seeing or even hearing from relatives on the other side of the border.
The two Koreas organised the first official reunion for separated families in 1985, but that was followed by a 15-year gap before the next gathering was held.
In the interim, some individuals set up private organisations to help South Koreans meet their relatives in the North, and sometimes arranging reunions in third countries - mainly China.
Mr Shim started his group in 1998 after meeting his North Korean brother. The work involved setting up an underground network of "helpers" in China and North Korea to help make the initial family- to-family contact. Most reunions take place in safehouses near the China-North Korea border.
"It's basically a question of money because getting relatives safely in and out of North Korea requires a lot of bribes," Mr Shim said.
For the past 15 years, groups like Mr Shim's have received financial aid from the South Korean government, which includes 7 million won (S$8,500) per family.
As risky and costly as these private reunions are, they allow the divided families to spend several intimate days together. The state-run reunions permit only 12 hours of face-to-face time over three days, mostly with monitors around.
After Mr Kim Jong Un came to power in 2011, North Korea tightened security on its China border, and the annual number of private reunions fell into single figures.
"It takes so much more to bribe the guards, and ordinary families really can't afford the expense" of such meetings, Mr Shim said.
But probably the biggest factor behind the slump in private reunions is the dwindling number of South Koreans asking for them.
"The old ones, the ones with brothers and sisters, are simply dying out," Mr Shim said.
"It's sad to say, but I think in another 10 years or so, the issue of separated families will have largely faded out."