Jurors are being selected in the Old Bailey trial of three Bulgarians accused of an international plot to spy for Russia.

Katrin Ivanova, 33, Vanya Gaberova, 30, and Tihomir Ivanov Ivanchev, 39, have denied a charge of conspiracy to spy between August 30 2020 and February 8 2023.

The charge alleges they conspired together and with a Russian agent using the alias “Rupert Ticz”, and others unknown, to obtain, collect, record, publish or communicate documents or information which was intended to be directly or indirectly useful to an enemy for a purpose prejudicial to the safety and interest of the State.

Ivanova has denied a second charge of possession of false identity documents with improper intention under section 4 of the Identity Documents Act 2010.

On Wednesday, Mr Justice Hilliard addressed groups of potential jurors in the case, which is due to go on until February 21 2025.

He told them: “This case concerns an allegation of spying, namely surveillance of individuals and places all of which it is said were of interest to the Russian state and the passage of information about those individuals and places to the Russian state via an agent of Russia.

“The activity is said to have taken place between August 30 2020 and February 8 2023 and in locations including London, Vienna, Valencia, Montenegro and Stuttgart.

“Some of those involved are also said to have been in possession of false identity documents for use when spying.”

The judge said the defendants were Bulgarian and would be wearing headphones in the dock so they can hear a translation of proceedings.

At the time of the alleged offences, Ivanchev was living in Acton, west London, Ivanova was living in Harrow, north-west London, and Gaberova in Euston, north London.

At the completion of the jury selection process, jurors will be sworn in and prosecutor Alison Morgan KC is expected to open the case on Thursday.