Russia's capital will stage the next leg of this year’s first cluster of events following the opening two meets in Paris-Chartres and Berlin.

The decision to continue hosting the event in Russia's capital is a controversial one following widespread allegations of state-sponsored doping there. 

The two-day event is scheduled to feature the likes of Hungary’s Katinka Hosszú and Russia’s Vladimir Morozov.

Both have been in dominant form so far, with triple Olympic champion Hosszú claiming 14 medals in the first two events and Morozov breaking the world record in the men's 100 metres individual medley twice in as many attempts.

Morozov is entering four races in his home country whilst Hosszú has entered all 17 available events possible, yet it remains to be seen how many she will actually take part in. 

Hosszú's potential lineup includes 50m, 100m and 200m swims in butterfly, backstroke and breaststroke, 100m, 200m and 400m individual medleys and 50m, 100m, 200m, 400m and 800m freestyles for women. 

Morozov will take on the 50m and 100m freestyle, 100m backstroke and will look to break the 100m individual medley world record for the third time in the World Cup.

Jamaican breaststroke swimmer Alia Atkinson does not appear on the entry lists. 

Atkinson tied a world record in the 100m breaststroke at the series opener in Paris last month, but does not plan to compete in Moscow. 

That could have big money implications as Atkinson is currently second in the women’s points and in line for a $35,000 (£26,000/€31,000) bonus. 

In order to claim the bonus, however, a swimmer has to swim all three legs of a cluster, so an absence in Moscow will cost her dearly.

As the first cluster of the tour is about to end, the top six men and women in series points will all earn big bonuses. 

In the men's competition Russia's Kirill Prigoda and Australia's Robert Hurley and Mitch Larkin are all tied for the final bonus position. 

In the women's tournament, Germany’s Franziska Hentke is also absent from the entry lists, meaning she has forfeited her position in the standings and therefore her bonus.

The second cluster features gatherings in Beijing, on September 30 and October 1, followed by Dubai on October 4 and 5, and Doha on October 8 and 9.

The final cluster sees the World Cup head to Singapore on October 21 and 22, with Tokyo playing host on October 25 and 26 and Hong Kong staging the last leg on October 29 and 30.

Additionally, various bonuses for establishment of world records and milestones will be awarded.

Twelve points are awarded for victory in each individual event, with nine for second and six for third.