North Korean leader Kim Jong Un, whose absence from public view fueled several rumors about the country's future, was away for a surgery to remove a cyst from his ankle, according to South Korea's intelligence agency. Kim was last seen in public on Sept. 3 and reappeared on Oct. 14, with a cane.

A foreign doctor conducted the surgery on Kim's right ankle in September, South Korea's Yonhap News agency reported Tuesday, citing government officials. The cyst could recur because of Kim’s weight, his smoking and busy public schedule, according to the South Korean National Intelligence Service, The Associated Press reported. Kim’s six-week long disappearance from the public eye had sparked several rumors about his well-being, including one about a possible coup. It was not clear how the spy agency obtained the information. 

The agency also said, according to AP, that North Korea had expanded five of its camps for political prisoners so that they could now hold nearly 100,000 prisoners.

The agency also reportedly said that the reclusive North had recently executed several people close to Kim’s uncle, Jang Song Thaek, by firing squad. Jang was the second most powerful person in the country before his sudden execution in December 2013.

South Korea’s spy agency has had a contestable track record so far. In 2010, the agency’s director admitted that it had ignored intelligence hinting that the North was going to shell a South Korean island. The agency also did not hear about the 2011 demise of Kim Jong Il, Kim’s father, for over two days until state media announced it globally, AP reported.