Kim Jong-Un aunt Kim Kyong-Hui emerges after husband Jang Song-Thaek executed College students wearing masks of North Korean leader Kim Jong Un, left, and his uncle Jang Song Thaek, centre, perform during a press conference denouncing Kim's dictatorship and alleged human rights violations against North Koreans in Seoul/. NORTH Korean dictator Kim Jong-Un's missing aunt has surfaced, after her absence from her husband's funeral since he was executed sparked concerns. Kim Kyong-Hui appeared to have returned home last month after receiving treatment abroad for heart disease, according to reports. The whereabouts and status of Kim Kyong-Hui have been a focus of media attention after her husband Jang Song-Thaek was executed last week in the biggest political upheaval since the young leader inherited power two years ago. Kim Kyong Hui, the aunt of North Korean leader Kim Jong Un, claps hands with other delegates during the ruling Workers' Party representatives meeting in Pyongyang, North Korea. "To my knowledge, Kim Kyong-Hui had been receiving treatment for heart disease and returned to North Korea last month," a diplomatic source in Beijing told Yonhap news agency. There was no indication of where she was treated but earlier reports have said she had sought treatment in Singapore on several occasions. Jang's widow had been named by state media last week as attending an official function, suggesting she may have survived the purge of Jang associates. But she apparently missed a crucial political event Tuesday on the second anniversary of the death of her brother and former leader Kim Jong-Il. North Korean leader Kim Jong Un, left, along with his aunt Kim Kyong Hui, right, attends a statue unveiling ceremony in Pyongyang, North Korea earlier this year. Jang's execution raised questions about factional infighting at the top of the Pyongyang hierarchy and prompted both Seoul and Washington to warn of possible provocative acts by the nuclear-armed North. Jang and his wife were once regarded as playing a key role in bolstering the leadership of the young and inexperienced leader. But Kim Kyong-Hui, 67, has been less visible in the past year, with reports saying she was seriously ill. News of her recent medical treatment comes after former NBA star Dennis Rodman touched down to train North Korea's national basketball team. Former NBA basketball star Dennis Rodman holds a cigar as he speaks to North Korean basketball players during a practice session in Pyongyang, North Korea. It also comes as North Korea has threatened a "merciless" strike against the South after activists burned effigies of the ruling Kim dynasty on the second anniversary of the death of former leader Kim Jong-Il, officials said Friday. The warning was contained in a message sent Thursday by the secretariat of the National Defence Commission, the North's highest military body, through a military hotline, the South's defence ministry said. Retired U.S. basketball star Dennis Rodman said he was not going to North Korea to talk about politics or human rights, almost a week after the execution of leader Kim Jong Un's uncle. In rallies on Tuesday to mark the death anniversary of Kim Jong-Il, South Korean conservative groups burned effigies of young North Korean leader Kim Jong-Un, his late father and grandfather. The North said the rallies had insulted the "highest dignity" of its leadership, and threatened to take "merciless" retaliatory acts without prior warning, the defence ministry said. "We've sent a reply vowing to react sternly to any provocations by North Korea," ministry spokesman Kim Min-Seok told reporters. The North's threat comes at a time of growing concern over the regime's stability after last week's execution of Jang Song-Thaek, a high-level official who was the uncle and former political mentor of Kim Jong-Un. Seoul and Washington have warned of possible provocative acts by the nuclear-armed North. North Korea has a long history of bellicose rhetoric, regularly threatening strikes against South Korea. Tensions between the two Koreas had appeared to cool down after soaring in February, when the North carried out its third underground nuclear test in defiance of UN Security Council resolutions. But relations have soured again in recent weeks