Former South Korean President Lee Myung-bak (R) talks with United Arab Emirates' Crown Prince Sheikh Mohamed Bin Zayed Al Nahyan in 2010. Photo: AFP

Korea JoongAng Daily reports that an influential adviser to the royal family of the United Arab Emirates (UAE) visited South Korea on Monday fanning further speculation about a possible scandal involving the two countries.

Attention has been growing since Im Jong-seok, South Korean President Moon Jae-in’s chief of staff made an unexplained visit to the Persian Gulf nation last month. Some say the hasty diplomatic trips are tied to a nuclear plant that South Korea is building in the UAE or the uses of a contingent of South Korean troops currently stationed in the country.

Khaldoon Al Mubarak, chairman of the Executive Affairs Authority of Abu Dhabi and chairman of the Emirates Nuclear Energy Corporation, reportedly arrived at Gimpo International Airport on Monday morning on a private jet.

JoonAng says the purpose of Al Mubarak’s visit is unknown. The Blue House refused to confirm any information about the UAE leader’s visit.

Moon unexpectedly dispatched Im to the UAE in December as his special envoy. South Korean officials initially said that Im’s trip was meant to cheer up Korean troops deployed in the Middle East, but the explanation was later withdrawn.

Im reportedly met during his trip with Sheikh Mohammed bin Zayed bin Sultan Al Nahyan, the crown prince of Abu Dhabi, and Al Mubarak.

No credible information has emerged on what precipitated the high-level diplomatic exchanges. Opposition politicians have speculated that bilateral relations must have been harmed in some way and that Im was sent to mend ties.

JoongAng says Seoul’s ties with the UAE rapidly advanced under the 2008-2013 presidency of Lee Myung-bak. The two nations are said to have formed a strategic partnership during Lee’s visit to the country in 2009.

Korea also won a US$18.6 billion deal to build the UAE’s first nuclear power plant at that time and construction of the project is still ongoing. Korea also sent the Akh Unit, about 150 troops including special forces and counterterrorism troops, to the UAE in 2011 at the request of the UAE’s crown prince.

Opposition critics reportedly said the nuclear reactor project is at risk due to allegations of corruption.

Other unconfirmed reports hinted that problems arose after a Moon administration attempt to change a secret military cooperation deal between the two countries backfired.

Government sources have been quoted as saying that a secret agreement was made between Seoul and the UAE under the Lee administration in which South Korean troops would intervene if a military situation occurred in the UAE.

The Moon administration wanted to change the terms, the sources were quoted as saying, and the UAE strongly objected, prompting Im’s trip in December.

“The Lee government proposed the military cooperation deal, which amounts to a mutual defense treaty, to the UAE in order to win the nuclear plant bid,” a government official told the JoongAng Ilbo on Sunday.