Two North Koreans have been found dead in separate rooms in the same Moscow hotel amid reports they both suffered 'acute heart failure'.

The men had complained of severe chest pains and shortness of breath before they died on Saturday at a hotel in the west of the Russian capital.

A police probe led by the country's equivalent of the FBI has been launched as it emerged that two more North Koreans staying in the same building are in hospital.

Two North Koreans have been found dead in separate rooms in the same Moscow hotel amid reports they both suffered 'acute heart failure'. An ambulance is seen driving near the scene

The men had complained of severe chest pains and shortness of breath before they died on Saturday at a hotel (pictured) in the west of the Russian capital

The first man to die was named as Chkhe Men Sen, 37. When paramedics arrived at Gorodskoy Hotel in Yermakova Roscha Street in central Moscow, he was already dead. The inside of one of the hotel's rooms is pictured

Five other non-Russian men are believed to be ill but their nationality has not been given.

The first to die was a 37-year-old with a name translated as Chkhe Men Sen. When paramedics arrived at Gorodskoy Hotel in Yermakova Roscha Street in central Moscow, he was already dead.

Soon afterwards a 22-year-old with a name translated as Khon Gim Chkol died as ambulance doctors sought to resuscitate him. The men were in separate rooms.

Two other North Koreans aged 34 and 41 had a 'fever of unknown origin' - and were taken to a Moscow infectious disease hospital. Their condition is not known.

Initial reports in Russia mentioned a viral infection, but later reports said the two North Koreans had died from 'acute heart failure'.

Five other residents of the dormitory were allowed to remain there on condition they reported immediately any changes in their condition.

North Korean officials have since 'removed' an unknown number of their fellow citizens from the hotel, it has been claimed.

Two other North Koreans aged 34 and 41 had a 'fever of unknown origin' - and were taken from the hotel (pictured) to a Moscow infectious disease hospital. Their condition is not known

Russian health watchdog Rospotrebnadzor as well as police and the Investigative Committee - seen as an equivalent of the FBI - are investigating the cause of the sudden illness

The deaths were overnight between Friday and Saturday, according to Russian reports.

Russian health watchdog Rospotrebnadzor as well as police and the Investigative Committee - seen as an equivalent of the FBI - are investigating the cause of the sudden illness.

The hotel offers 'dormitory accommodation' and rooms for low income immigrant workers in the Russian capital, where many work on building sites.

Pictures posted by immigrant workers from Tajikistan show conditions at the hotel, which is located close to the downtown skyscraper Moscow City district, where there are many building sites.

Rustam, who said he was the 'new manager' of the hotel, told MailOnline: 'No comment on the number of people who died.

'There are no illnesses in our dormitory, and I will not be speaking about earlier reports. As for how many citizens of North Korea live here, the answer is none. They have all left.

'All North Koreans were taken from the dormitory by their chiefs, there are none of them left.

'When and why? How many of them stayed here? Where did they go? I don't know. Talk to their chiefs.'

There has been no comment from the North Korean embassy.

Two North Koreans have been found dead in separate rooms in the same Moscow hotel amid reports they both suffered 'acute heart failure' (file picture)

It comes just months after the half-brother of North Korean dictator Kim Jong-un was murdered at Kuala Lumpur airport in Malaysia.

Assassins targeted Kim Jong-nam using a deadly nerve agent.

While Malaysia never directly accused North Korea of carrying out the attack, speculation is rampant that Pyongyang orchestrated a hit on a long-exiled member of its ruling elite.

Although Kim, who was estranged from his family, was not an obvious political threat, he may have been seen as a potential rival in the country's dynastic dictatorship.

North Korea has denounced such speculation and has never acknowledged the victim was a member of its ruling family.

This morning, an Indonesian and a Vietnamese woman accused of carrying out the killing appeared in a Malaysian court Tuesday, wearing bullet-proof vests and under heavy security.

It comes just months after Kim Jong-nam (pictured), the half-brother of North Korean dictator Kim Jong-un, was murdered at Kuala Lumpur airport in Malaysia

Both women, aged in their twenties, could face the death penalty, though they have denied murdering Kim Jong-Nam, saying they were duped into believing they were taking part in a reality TV show.

Seoul accuses North Korea of being behind the February killing, a charge Pyongyang denies.

Indonesian Siti Aisyah, 25, and Vietnamese Doan Thi Huong, 28, appeared for Tuesday's pre-trial hearing, during which their defence lawyers slammed the prosecution for failing to furnish them with relevant documents.

'The concept of a fair trial demands that all material documents should be supplied to the defence at the earliest opportunity,' Gooi Soon Seng, chief lawyer for Siti Aisyah said.

Deputy public prosecutor Muhammad Iskandar Ahmad assured the defence they will be given the documents before the trial.

The High Court is expected within a month to fix a date when the accused will enter a plea. Prosecutors and defence lawyers will then have 60 more days to prepare for the case, after which the trial dates can be determined.

The Magistrate Court's judge also approved a prosecution request that the case be moved to the High Court for the trial.

Malaysian police accuse the women of wiping the banned nerve agent VX on Kim's face as he was about to board a flight from Kuala Lumpur to Macau, where he was living in exile.

Police are still trying to trace four North Koreans suspected of having taken part in the murder plot, who are believed to have returned to Pyongyang immediately after the killing.

The murder sparked a diplomatic row between Malaysia and North Korea.