North Korean leader Kim Jong-un's wife thought to be 'pregnant with second child'

Ri Sol-ju was seen wearing a maternity dress at a recent sporting match

A photo released by North Korea's media in 2013 shows Kim Jong-un and his wife Ri Sol Ju. (KNS/AFP/Getty Images)

Ri Sol-ju, the wife of the North Korean leader Kim Jong-un, is thought to be pregnant after she was seen wearing a maternity dress.

Experts say the leader is desperate to father a son, as it is “impossible a daughter could take over" as the head of the dynasty.

A photograph taken at a recent sporting event in Pyongyang, featured on the 18 February front page of the state-run Rodong Sinmun newspaper, shows Ri wearing loose-fitting clothes, according the Telegraph.

“There have been rumours that Ri is pregnant again for a few weeks now,” Toshimitsu Shigemura, a professor at Tokyo's Waseda University and an authority on North Korean affairs, told the newspaper.

“This is not really a surprise as Kim needs a son as a successor for the dynasty that has ruled North Korea since it was founded by his grandfather, Kim Il-sung.

"It's absolutely impossible that a daughter could take over as leader, so his wife needs to give birth to a son,” he added.

Ri appears to have stopped attending public events with her husband in recent weeks, as she did during her first pregnancy in 2012.

Photos of the couple's first baby have not yet been published, which experts say is due to the ongoing three-year period of official mourning for Kim's father, Kim Jong-il, who died in December 2011.

Kim is also believed to have a fathered another daughter with separate woman in 2010.