A Russian spy cell operating in the UK planned to kidnap a journalist and smuggle him out of the country using a small boat, the Old Bailey has heard.

The court has heard that Jan Marsalek, an Austrian national who acted as a Russian agent, exchanged thousands of messages with Orlin Roussev from Great Yarmouth.

Roussev, 46, and another man, Biser Dzhambazov, 43, from London, have admitted conspiracy to spy.

Katrin Ivanova, 33, Vanya Gaberova, 30, and Tihomir Ivanchev, 39, all from London, deny conspiracy to spy. Ms Ivanova also denies possessing multiple false identity documents.

Jurors have heard the five Bulgarian nationals were involved in six operations against individuals and places of interest to the Russian state over nearly three years.

The trial has been told the defendants worked under the direction of Roussev, and that he, in turn, received instructions from Jan Marsalek, who was working as an “intermediary for the Russian intelligence services”.

One target was Roman Dobrokhotov, a Russian investigative journalist based in the UK, the court has heard.

Jurors heard about messages between Roussev and Marsalek in August 2022 about getting Mr Dobrokhotov out of the UK via boat.

Roussev wrote: “I will brainstorm with Max [Dzhambazov] about Operation “Fishing Boat” for Roman Dobrokhotov end of week”.

Marsalek told him that a “successful operation on British ground would be amazing” after the failed nerve agent attack on Sergei Skripal in Salisbury.

Mr Skripal, his daughter Yulia and former police officer Nick Bailey were poisoned by Novichok in Salisbury, Wiltshire, in March 2018 but survived. Dawn Sturgess, 44, died in July 2018 after she was exposed to the nerve agent, which had been left in a discarded perfume bottle in nearby Amesbury.

The court heard there was discussion between Roussev and Marsalek about private boats from Norwich and Hull.

Roussev also wrote that “operation ‘boat trip”’ would involve four people and him, adding that “everything will be IN-HOUSE”

He said those involved would be “Max + Ivan”, meaning Dzhambazov and a man called Ivan Stoyanov, plus “one more SWAT guy from Bulgaria (this is Commando Unit) and a 68y old and very very experienced ‘Sea Wolf’ from Bulgaria, old school guys retired Navy expert from the Old Soviet time”.

Roussev added: “He has 2 small boats and he had been running just for personal fun a lot of boat races between Southampton and Spain/Portugal”.

The court also heard that Marsalek said one of his alleged operatives was “afraid of Novichok” after she passed on the mobile pin number of Mr Dobrokhotov.

Messages read to the jury related to a flight taken by Mr Dobrokhotov in November 2021, which Ms Ivanova followed him onto, allegedly using a camera hidden in a shoulder strap.

Ms Ivanova sent live updates to a group chat, which included Roussev, about Mr Dobrokhotov’s activity on the flight, including that he had two phones, was using social media, and that he “listened to music and played Sodoku”.

She provided a pin number she watched him entering into a mobile phone, which jurors heard was correct but for an additional wrong digit at the end.

Roussev then passed on details to Marsalek, writing: “Our “agent” was very observant” and giving the phone’s “lock code”.

In response, Marsalek wrote: “Afraid of Novichok” along with a smiley face emoji.

The court was also read messages between Roussev and Marsalek about a potential surveillance operation in Ukraine relating to investigative journalist Christo Grozev, another target of the cell.

The messages were from February 2022, just weeks before Russia’s invasion of Ukraine that month. At first the two men discussed plans but shortly afterwards Marsalek wrote saying the operation would not be possible.

Marsalek wrote: “Our friends are worried our presence might interfere with another overlapping operation in Ukraine”.

He added: “They would prefer if we’d abstain from any on the ground activity in Ukraine at the moment.”