On June 5, 2016, Denis Ogienko returned to Moscow following a three-day trip in Lipetsk. The European Sambo champion allegedly stepped out of his friend's car in front of his own house in the Tyolpy Stan district, bid goodnight, and was never seen again.

It is a mystery that puzzled police and bewildered the local community. Ogienko, a 36-year-old retired athlete who lived with his common-law wife and child, was a known figure in the neighbourhood. When Ogienko did not turn up for another two weeks, investigators suggested that the successful athlete may have been the victim of a gang-related crime.

But why was a children's Sambo coach targeted by gangs? Coincidence, or part of a series of dark secrets to emerge from the legendary 'Sambo-70' gym in the past year?

Back in April 2016, law enforcement officials in Makhachkala arrested several members of a drug cartel selling "synthetic smoking mixtures" known as 'Spice' throughout the region. All of the arrested offenders were Dagestan natives residing in Moscow. All of them were renowned athletes and Masters of Sports (prestigious title given to national champions in respective sports) from the Sambo-70 club.

Police seized more than two kilograms of the synthetic drug in one raid. The estimated worth of the product was 30 million rubles. In an official statement, law enforcement noted that the drug dealers lived lavish lifestyles in Dagestan's capital city, with large properties and multiple luxury cars. They now face between 20 years and life imprisonment on trafficking charges.

Six drug dealers were involved. None were named, though Russia's Federal Drug Control Service confirmed reports that they were "famous athletes" from Sambo-70.

The plot thickened.

Founded in 1970, Sambo-70 rose to become one of the largest combat sports schools in the Soviet Union, and later the Russian Federation. The school quickly branched out to other sports, including gymnastics ice skating. Countless Olympic, World, and European champions emerged over 22 sports from this one particular school. What once started as a small gym with raggedy carpets eventually became the largest centre for sports education in Moscow.

To get a grasp of the significance of this particular Sambo school, here is Russian president Vladimir Putin's congratulatory letter to Sambo-70 for their 45th anniversary in 2015.

In 2010, Sambo-70 ventured into MMA and created the S-70 league to "convey the values and the foundations on which the renowned Russian school of martial arts" is built. Over the years, the promotion - mainly an annual event - featured the likes of Alexander Shlemenko, Alexander Sarnavskiy, Andrey Koreshkov, Vitaly Minakov and countless other Russian talents. The events were also regularly attended by Putin and other Russian politicians.

Given the exemplary reputation that Sambo-70 had acquired over the years, the string of troubling reports offers an interesting contrast. Drug busts and mysterious disappearances should not be standard practice at well respected, state sponsored schools.

However, within the span of three months, six of the club's members have been arrested, while another has gone missing, presumed dead.

Reports on Ogienko disappearance vary, as surveillance cameras in the area did not show him in his friend's car when they returned from their three-day trip. Friends and family are less than trusting of the friend's overall account, though it quickly became clear that Denis had a troubled background.

"The last time one saw Denis, he was being driven to Moscow. Denis himself was badly drunk, but they brought him straight to the house. Dennis' girlfriend filed a complaint with the police and stated that he was inclined to drunkenness and loss of memory, but friends of Dennis refuted this version." according to Bloknot.ru.

The same report also revealed that Ogienko, a three-time Russian champion, European champion, and Master of Sports in Judo and Sambo, also worked for the Ministry of Internal Affairs.

Given that athletes who later join law enforcement become targets of gang-related violence, it comes as little surprise that Ogienko could potentially be the latest victim of longstanding tension between the two entities. In Dagestan, countless athletes lost their lives because of varying degrees of relationships with law enforcement and political figures. It is a cursed path that eventually leads to a bloody demise.

Sambo-70, however, has had little to say on the matter. Despite an unprecedented stretch of negative publicity, the Moscow powerhouse in sports education is perfectly prepared to ignore the current proceedings. No statements have been released regarding the alarming criminal activity associated with several of their prominent members.