North Korean leader Kim Jong Un missed an important national celebration Friday, stoking speculation the dictator has fallen ill or been deposed by a coup after he disappeared from public view more than a month ago.

Kim did not appear at the founding anniversary of North Korea’s ruling Workers’ Party on Friday, according to an attendance list released by the state news agency. Unofficial reports tell the Associated Press that Kim remains in charge of North Korea and is laid up with a leg injury. Still, it’s the first time he’s missed the Worker’s Party anniversary since he came to power in 2011, and some are suggesting his absence could indicate trouble within the country’s power structure.

Kim Jong Un last appeared on North Korean television Sept. 3, when he attended a concert with his wife. He was recently filmed walking with a limp and looking heavier than usual, but North Korea’s propagandistic news agency has not shown the leader since.

University of British Columbia professor Hyung-Gu Lynn says Kim Jong Un sent flowers to the anniversary in lieu of his absence on Friday.

“Today’s newspapers in North Korea were filled with laudatory references to him,” added Lynn, a professor at UBC’s Institute of Asian Research.

Lynn says Kim’s absence was likely due to an ankle injury.

“The best explanation is that Kim Jong Un has a health problem, and that his recovery process has been slower than anyone inside the country has anticipated,” he told CTV News Channel on Friday.

Sources from inside the secretive, tightly-controlled country have downplayed Kim’s absence, describing his apparent leg injury to AP as a “discomfort” that needs time to heal. Kim allegedly pulled a tendon while participating in military drills with the North Korean army, and aggravated the injury by trying to walk with it.

“By all indications, he’s alive and in control of the country, but just not in the greatest of health,” Lynn said.

North Korea’s neighbours to the south also appear unconcerned about Kim’s absence. South Korean officials say a recent visit from the North’s top general, Hwang Pyong So, shows Kim still holds the reins of power.

Hwang was in South Korea for the opening of the 2014 Asian Games in September. The North Korean athletes at the event also reportedly paid tribute to Kim, in a sign that he is still in charge.

But speculation continues to swirl around the 31-year-old North Korean dictator, whose family has a history of internal intrigue and subterfuge.

A number of theories are circulating about the fate of Kim Jong Un, but the state-run news agency has been mum about his real whereabouts.

Poor health

Kim Jong Un’s limp has led to much speculation regarding his health. Aside from an ankle injury, diabetes or gout could also cause a person to limp.

Lynn says Kim’s weight may contribute to his ankle problems. Kim Jong Un is five-foot-seven and 220 pounds (100 kilograms), according to Lynn. That translates to a body mass index of 34.5, which health experts consider to be obese.

According to Lynn, the gout rumours spring from Kim’s long history of smoking and drinking, which he reportedly started doing at a young age. Lynn adds that Kim may even have psychological issues, but it’s impossible to know for sure.

“We really don’t have that much information about North Korea or Kim Jong Un’s health,” he said.

Though Kim’s whereabouts remain unknown, Lynn says South Korea has seen French, Russian and German doctors flying into North Korea in recent weeks.

“We don’t know for certain who or what they were treating,” he said.

Late last month, a South Korean news outlet cited sources in the North saying Kim had gout.

Public image has been a huge part of the Kim family’s rule in North Korea. As North Korea’s ‘Supreme Leader,’ Kim Jong Un could be staying out of sight so his limp does not make him appear weak.

Power shift

Some have said Kim Jong Un’s younger sister, Kim Yo-jong, could be running the country now. Kim Yo-jong was introduced as a senior official in the ruling Worker’s Party last March, and is believed to be one of Kim Jong Un’s chief advisors.

If Kim Jong Un has died, Kim Yo-jang could be capable of seizing power. It’s believed Kim Jong Un has a daughter, but that child is still an infant.

The military could also seize control of North Korea, but Hwang Pyong So’s visit to the South last month shows that he, at least, is still loyal to Kim.

Lynn points out that North Koreans have only ever known the Kim family as their rulers. The country was founded by Kim Jong Un’s grandfather, Kim Il Sung, in 1948. Kim Il Sung named his son, Kim Jong Il, as the new ruler of North Korea in 1994. When Kim Jong Il died in 2011, Kim Jong Un ascended to become leader of the country.

Family tree

The Kim family has a complicated history. Kim Jong Un’s aunt, Kim Kyong-Hui, has not been seen for years, but she was once a top advisor to Kim Jong Il. She disappeared in 2013, shortly after Kim Jong Un ordered her husband’s execution.

Kim Jong Un himself was not always first in line to take over from his father. Kim Jong Un’s oldest sibling, a half-brother named Kim Jong Nam, was deemed unfit to rule, and he now lives in exile in China. Kim Jong Un’s other sibling, Kim Jong Chul, reportedly still lives in North Korea. He has rarely been seen in public since Kim Jong Un took over.

Kim Jong Un’s younger sister, Kim Yo-jong, now serves as one of his advisors.

Wilder theories

As with his father Kim Jong Il before him, Kim Jong Un has often been a subject of mockery in popular culture. In the month since Kim’s last appearance, social media users have had plenty of not-so-serious theories as to where he’s been.

One Twitter user even mentioned the James Franco-Seth Rogen film ‘The Interview,’ a fictional story about the pair going to North Korea to Kim Jong Un under the guise of conducting an interview.

With files from The Associated Press