A journalist targeted by a Russian spy ring said it had a list of “assassination methods” to kill him that was “beyond any imagination”.

Christo Grozev told the BBC the group “fantasised” about his death, and talked about using a sledgehammer and even a “suicide bomber” to target him.

The Bulgarian, who has published several exposés on Russia with colleague Roman Dobrokhotov, said several incidents showed the pair were tracked across Europe and had agents “breathing down our necks”.

He was speaking after three Bulgarian nationals were found guilty last week of spying for Russia one of the largest foreign intelligence operations in the UK.

• How spy ring did Russia’s dirty work from the UK

Mr Grozev said that since the court case, Austrian police had reassured his children that this not could not happen again, adding that initially his family had been “shocked”.

Speaking to BBC Radio 4’s Broadcasting House programme, he said the “list of imagined assassination methods” on his life “reads like a film noir”.

He said one of the ways the spies “fantasised about killing me” was hiring an Islamic State group “suicide bomber and having him explode himself next to me in the street”.

Mr Grozev said there was also a plan to kidnap him and “send me to a torture camp in Syria” while another man wearing a latex mask resembling him would fly to Russia on a commercial flight and be “arrested in front of cameras for full deniability”.

“Another way was bludgeoning me to death using a sledgehammer”, he said before adding that “the fantasy and imagination of these wannabe spies is beyond any imagination”.

Mr Grozev said failures of Russian intelligence in the past meant that spying was being “outsourced” to non-professional spies.

He told the BBC that the fact they were using “non-professional” spies did not take away from the “intent to kill”. The issue was that “wannabe spies” did not necessarily know how to de-escalate situations, he added.

He said he felt lucky to be alive given that he and his colleague were tracked by the spies for so long and the operation had been so well-funded. He and Mr Dobrokhotov were never on the lookout for EU citizens spying on them, but they had expected that Russian operatives would be observing them, he added.

The pair’s work includes exposing Russia’s role in the nerve agent attacks on then-Russian opposition leader Alexei Navalny in 2020 and Sergei Skripal in Salisbury in 2018.

Jan Marsalek, who instructed the spy ring on behalf of the Russian intelligence services, wrote in a message in December 2020 that Mr Grozev was the “lead investigator in the Navalny case”.

A message sent by Marsalek to Orlin Roussev – who ran the UK-based group from a former guest house in Norfolk – said: “Personally I find Grozev not to be a very valuable target but apparently Putin seriously hates him.”

After 2020, the spy cell followed the two journalists throughout Europe, spying on them on planes, in hotels and private properties.

On Friday, three spies were found guilty of spying for Russia in one of the largest” foreign intelligence operations in the UK.

In court, it came to light that operatives from the spy ring entered Grozev’s flat in Vienna in 2022 “when my son was playing a computer game in his room”, the journalist said.

He added: “I just don’t want to think about what would’ve happened if my son decided to go out of his room during their burglary.”

On Friday, Vanya Gaberova, 30, Katrin Ivanova, 33, and Tihomir Ivanchev, 39, were found guilty of conspiracy to spy. While the trio had day jobs as a beautician, a healthcare worker, and a decorator, the cell they were part of plotted to kidnap and kill targets, as well as planned to ensnare them in so-called honeytraps.

The methods they used were the sort of thing you would “expect to see in a spy novel”, said the Metropolitan Police’s Cdr Dominic Murphy.