MOSCOW (Reuters) - Siberian authorities on Tuesday revised upwards the number of Russians who have died after drinking contaminated bath oil to 52 from 41, the Irkutsk region’s health ministry told Reuters.

A further 29 people are in hospital, some of whom are in a serious condition and may die, a spokeswoman for the ministry said.

The poisoning in Irkutsk, a hard scrabble city around 2,600 miles (4,000 km) east of Moscow, is one of the worst such cases in recent years in a country where up to 12 million people use cheap surrogate spirits.