Rooney and Kate Mara have been spotted filming in Dublin for German director Werner Herzog's upcoming film Bucking Fastard, according to The Sunday World.

The tabloid has published photos of the American siblings during shooting on Dublin's Capel Street.

In the film, Rooney and Kate play twin sisters and social outcasts Joan and Jean. The script has been written by Herzog and is reportedly inspired by real events.

"I want to make a feature film about the twins Freda and Greta Chaplin," said the filmmaker in an excerpt from his recent book Every Man for Himself and God Against All: A Memoir, quoted in the tabloid.

"In 1981 they had a short run in the British 'red tops,' or tabloid newspapers, and were famous for a few weeks for being the 'sex-crazed twins' who were so infatuated with their neighbour, a lorry driver, that he took them to court and had a restraining order taken out against them.

"Their story is unique," continued the excerpt. "They are the only identical twins we know of who speak synchronously."

The feature is the first major film in which the two sisters have worked together.

It is reported that filming has already taken place at Dublin's Pigeon House film studios, as well as at various other locations around the city and in Naas, Co Kildare.

Filming is set to continue in Dublin during the next two weeks, and additional scenes are set to be filmed in Slovenia.

Rooney Mara had her breakthrough in David Fincher's The Girl with the Dragon Tattoo (2011), which earned her a nomination for Best Actress at the 84th Academy Awards.

The actress professed her love for Ireland after filming Jim Sheridan's The Secret Scripture (2016) in the country. Both her and her sister are of Irish descent.

Kate Mara is known for her roles in TV shows such as House of Cards, 24 and American Horror Story: Murder House.