Poisonings caused by cheap surrogate alcohol are a regular occurrence, but the Irkutsk case was unprecedented in its scale.
Bottles with the lotion were clearly marked with warnings that they weren't for internal use but labels warned that the product contained ethyl alcohol rather than methanol, officials said.
A source from the Russian Investigative Committee said in a statement: "'It is now known that 42 people have been taken to hospitals, and 25 of them have died". Officials described the victims as socially disadvantaged people aged 35 to 50, including several women.
"It's an outrage, and we need to put an end to this", Mr Medvedev said. They were not drinking together, so this tragic incident doesn't look suspicious - it just fits into the situation which is already regular in Russian Federation. Anyway, every bottle of lotion was marked as potentially risky for internal use, but the warning was ignored.
Two people have been detained over the deaths, investigators said, and searches are being conducted at the markets where the deadly product was being sold.
The label on the bath oil said it contained ethanol, and people drank the product as a cheap alternative to alcohol, which is a common practice in Russian Federation, the Post reported.
The sale of lotions containing alcohol has been on the rise in recent years in Russian Federation as the country's economy has struggled in the face of the sanctions and a slide in oil prices.
At a cabinet meeting on Monday, Prime Minister Dmitry said authorities need to quickly ban such substances.