Script for finale of latest Downton Abbey series accessed by infamous hacker Guccifer

'Guccifer' apparently downloaded it from writer Julian Fellowes’ BT internet account as part of an assault on prominent individuals

Oliver Dimsdale and Lily James in Downton Abbey’s Christmas special

A notorious hacker, whose targets have ranged from George W Bush to the Watergate journalist Carl Bernstein, has also accessed the emails of two members of the House of Lords, including the actor and writer Julian Fellowes, it has been claimed.

The script of the finale to the most recent season of Downton Abbey was downloaded after the hacker, known as “Guccifer”, apparently accessed Lord Fellowes’ BT internet account as part of an assault on the private data of hundreds of celebrities, politicians, industrialists and other prominent individuals.

His British targets also included the former Attorney General, Baroness Scotland – whose personal emails were accessed – and the City financier Sir Francis Brooke.

Emails leaked last year suggest that the hacker had focused on the prominent American dynasties such as the Bush family or the Rockefellers. But a cache of documents handed to an American website, TheSmokingGun.com (TSG), shows that Guccifer, who last year released hacked images of paintings by the former American President, was more prolific than previously thought.

The latest list of victims includes the director of Romania’s domestic intelligence service, the comedian Steve Martin and John Negroponte, the former US ambassador to the United Nations. His British targets also included the actor Rupert Everett, the broadcaster Jeremy Paxman and the author Martin Amis, though it is unclear whether any of their data was accessed.

Julian Fellowes may have been hacked using details stolen from journalist Tina Brown (PA)

TSG, which normally specialises in reproducing crime-related documentation, said it had been passed the data trove because the hacker feared imminent arrest by the FBI.

A significant number of his victims, including Lord Fellowes, seem to have been targeted after their email addresses were found by Guccifer on a contact list of 900 names stolen from Tina Brown, the British-American editor of The Daily Beast and renowned Manhattan mover and shaker.

The website said that the hacker had accessed the script for the final episode of the fourth season of Downton last May, six months before it was shown on British television.

The modus operandi of Guccifer, whose identity is unknown to TSG, seems to have been as low-tech as it was effective. After getting hold of emails, he used publicly available information about targets gleaned from sites such as Wikipedia to try to guess their password security questions.

His disclosures have ranged from doodles by Bill Clinton to the first 50 pages of an unpublished novel by Sex and the City author Candace Bushnell, for which he gave a link from the writer’s own Twitter account.

Neither Lord Fellowes nor Baroness Scotland responded immediately to requests to comment on the hacking.