(Reuters) -Russian investigators have arrested and charged three people after more than 120 people in Moscow and dozens in other cities fell sick with food poisoning that authorities said was caused by botulism in a vacuum-packed bean salad.

The Rospotrebnadzor consumer safety watchdog said more than 172 metric tons of dangerous products had been removed from circulation after botulism cases were registered in Moscow, its surrounding region, and the regions of Nizhny Novgorod and Tatarstan.

Unsanitary conditions and substandard preparation of the bean salad, including a lack of centralised water supply, "led to a massive accumulation of botulinum toxin in the finished product," Rospotrebnadzor said in social media posts.

Botulism is a rare, life-threatening illness that attacks the body's nerves and causes breathing problems and muscle paralysis. The bacteria that triggers the sickness can enter the body in poorly preserved food.

Russia's Investigative Committee, which handles serious crimes, said it had arrested the head of a food production company, as well as the director and head of quality control for a food delivery service.

Interfax news agency said over 120 people had consulted doctors in Moscow after coming down with symptoms of poisoning and suspected botulism.

Nearly 30 people in Kazan and Nizhny Novgorod, cities east of Moscow, have also turned up at hospitals with botulism symptoms, Interfax reported.

Dozens of people across the three cities are in intensive care. An official in Moscow cited by Interfax said the patients were under constant monitoring and their symptoms were not life-threatening.

The Investigative Committee said it had determined the food companies had violated multiple sanitary and epidemiological standards, including failing to submit laboratory test reports and engaging in poor production control.

Investigators said they had also charged the people with facilitating the illegal migration of Uzbek nationals. Many food delivery workers in Russia are from Central Asian countries.

(Reporting and writing by Lucy Papachristou; Additional reporting by Elaine Monaghan in Washington; Editing by Mark Trevelyan and Rod Nickel)