German authorities are investigating a possible poisoning attack in Munich last autumn on a Russian dissident journalist who had written critical articles about her country’s invasion of Ukraine, the Berlin prosecutor has confirmed.

In an article published with Russian-language outlet Meduza and US publication n+1 on Tuesday night, journalist Elena Kostyuchenko said she was tipped off by a source in Ukrainian military reconnaissance last March about Russian plans to assassinate her.

Kostyuchenko, who was at the time reporting for the now-shuttered independent newspaper Novaya Gazeta from near Mariupol, Ukraine, initially managed to escape to Berlin.

On 17 October, the journalist travelled to Munich to apply for a Ukrainian visa to continue covering the war for Meduza, an independent news website headquartered in Riga in Latvia.

On her return train journey to Berlin, she started to experience symptoms of poisoning, including severe headaches, weakness, shortness of breath and nausea.

“The sweat smelled strong and strange, like rotten fruit,” Kostyuchenko said in her article. She later experienced a swelling of her face, fingers and toes.

Medical tests conducted 10 days after her first symptoms showed elevated liver enzymes five times higher than normal, as well as blood in her urine.

Kostyuchenko says she was later questioned by a German senior detective who had run the investigation into the killing of Zelimkhan Khangoshvili, a Chechen exile shot dead by a Russian assassin in a park in central Berlin in 2019.

“I can confirm that the Berlin prosecutor is investigating against an unknown perpetrator,” a spokesperson said.

After an investigation was initially closed in May this year due to lack of evidence of a poison attempt, they said, it was reopened in July.

The decision to reopen the investigation was due to “further considerations” of the circumstances rather than newly emerged evidence.

“We are checking whether an examination of further objects from the surroundings of the injured party could still be expedient at this point,” they added.

Kostyuchenko has won awards for her coverage of the 2011 Zhanaozen massacre, where at least 14 protesters were killed by police in an oil town in western Kazakhstan.

She has cited as her inspiration to enter journalism the late Russian Novaya Gazeta journalist and human rights activist Anna Politkovskaya, who was poisoned in 2004 and shot dead in 2006.

The Committee to Protect Journalists, a New York based-NGO, called on German authorities to transparently investigate the allegations raised by Kostyochenko. It also urged authorities in Georgia to investigate reports of a poisoning attempt on Russian radio journalist Irina Babloyan.

“Reports that Russian journalists Elena Kostyuchenko and Irina Babloyan may have been poisoned in Germany and Georgia are extremely alarming, and must be investigated at once,” said Carlos Martinez de la Serna, CPJ’s programme director.

“German and Georgian authorities should treat these allegations with the utmost seriousness and do all they can to safeguard the lives of journalists living in exile.”