Operations at the facility, the only economic link between the two Koreas, were suspended in early April at the height of tensions between the two countries. That action came after North Korea withdrew all its 53,000 workers, leaving 175 South Koreans, representing their 123 companies, at the complex.
South Korea's Unification Ministry said as of Monday, 43 out of the last batch of 50 South Koreans had returned home, while the other seven stayed back to settle accounting and other unresolved matters, Yonhap News reported.
"The North has asked for pay due for its workers for March, some overdue wages, unpaid corporate taxes by the 123 companies that have factories at Kaesong and outstanding communication service-related fees," a ministry official said.
Yonhap said while the official did not say how much the North was demanding, it could be about $7.2 million in wages owed based on a monthly average of $134 North Korean workers earned at the complex.
"What they are asking is not excessive," the ministry official said. He said the South would ask the North to allow companies to bring back finished goods still at Kaesong.
The latest developments come after the North last Friday turned down the South's offer of dialogue to resolve the issue. There also are concerns whether the facility, which began operating in 2004 providing much-needed economic benefit to the North, will ever reopen as tensions on the Korean Peninsula remain high even though the North's recent highly provocative threats have since eased.
A senior South Korean presidential official said the North is to blame for the crisis and Seoul has no intention of making any concessions on Kaesong.
The North's belligerence is in response to tightened U.N. Security Council sanctions over the North's Feb. 12 nuclear test, its third since 2006. The North, under its new and unpredictable leader Kim Jong Un, also is irate over the annual joint U.S.-South Korean military drills.
There are concerns in the South that the North may confiscate the assets of the 123 companies at Kaesong.
A separate Yonhap article said that since 2004, South Korea has invested about $1 billion in the complex. The report said using North Korean labor, South Korean investors have so far produced about $1 billion worth of garments, wristwatches and other labor-intensive goods there. In return, the North earned $245 million in wages.
One expert said if the North shuts down the facility for good, it would make it difficult for the administration of new South Korean President Park Geun-hye to push forward its trust-building policy.
"Counting the number of North Korean workers and their dependents, Kaesong supported roughly 200,000 people in the communist country," a Seoul government official told Yonhap, adding its closure could pose a serious problem for the impoverished nation and its leadership.
Some analysts said in view of such consequences, the two sides may try to reach some agreement on Kaesong at the last minute.