They were once the plaything of the Soviet Union's KGB state security service and its notorious overlord Lavrenty Beria, the right-hand man of Stalin.

But on Saturday, Dynamo Moscow, one of Russia's most celebrated football clubs, suffered the indignity of a first relegation since their founding in 1923.

"We're all very upset. It's the first time we're relegated in the club's 93-year history," Dynamo coach Sergei Chikishev said.

"Now we need to confer with the club chiefs to work out a plan for further action."

But the road back won't be easy for a club drowning in debts estimated to be close to $300 million.

It's a far cry from the days when they were the public sporting face of the KGB and were locked in a bitter rivalry with city rivals CSKA Moscow, the team of the Red Army.

On Saturday, CSKA were crowned Russian Premier League champions, rubbing further salt into the deep wounds of a team which once boasted legendary players such as goalkeeper Lev Yashin, Konstantin Beskov, Igor Chislenko, Viktor Tsarev and Mikhail Yakushin.

Dynamo played their first official match on June 17, 1923, representing the country's interior affairs ministry and later the State Security Committee, the KGB.

Dynamo won the Moscow football championship six times in 1926, 1928, 1930, 1931, 1934 and 1935 before the Soviet league was established.

They won the first Soviet title in 1936 and celebrated the double a year later, winning the championship and the Soviet Cup.

Dynamo also won the first championship staged after World War II in 1945 before visiting Great Britain in the same year, where they beat Cardiff City and Arsenal and played out a 3-3 draw with Chelsea and a 2-2 draw with Scottish giants Rangers.

More success followed. Dynamo dominated the Soviet league in the 1950s and became the first Soviet club to battle into a European final.

That was in 1972 when they suffered a 3-2 defeat to Glasgow Rangers in the final of the Cup Winners Cup.

In the post-Soviet era, however, Dynamo managed to win only one trophy -- the Russian Cup in 1995.

After years in the doldrums, Dynamo reached for the chequebook in 2014 by signing Mathieu Valbuena, Christopher Samba and other top European and Russian players.

They made the Europa League round of 16 and went on to finish fourth in the domestic league.

But their hopes of playing in Europe again were dashed by a UEFA decision to suspend the club for financial fair play violations.

The majority of European players and local stars soon left forcing Dynamo chiefs, who are mainly retired KGB generals, to promote players from the club's youth team.

Dynamo went down to the second division having chalked up just five wins and only 25 points.

Russia Olympic Committee chief Alexander Zhukov, however, said that the relegation may stand Dynamo in good stead.

"Taking into consideration the previous cases of top clubs being relegated, it may serve Dynamo good," Zhukov said referring to Spartak Moscow's case in the 1970s.

Spartak were also relegated in 1976, but won promotion just a year later and claimed the national title in 1979.