The research by Swansea University and The Sunday Times found about 6,500 automated accounts sent messages praising the opposition Labour leader Jeremy Corbyn and his policies in the closing stages of the election.
They also attacked Prime Minister Theresa May for refusing to take part in televised election debates and criticised her for cutting police numbers in the wake of the Manchester bombing.
The study found nine out of 10 messages from the accounts about Labour backed the party. In contrast, nine out of 10 tweets about the Conservatives were hostile.
The British government has accused Russia of meddling in elections around the world and planting fake stories in the media, but has denied Russia has successfully interfered in British elections.
Get the latest election news, live updates and election schedule for Lok Sabha Elections 2019 on ndtv.com/elections. Like us on Facebook or follow us on Twitter and Instagram for updates from each of the 543 parliamentary seats for the 2019 Indian general elections.