LONDON — An academic study set to be released on Tuesday casts doubt on speculation that Russia might have exploited social media to try to influence Britain’s 2016 referendum to leave the European Union.

Academics, lawmakers and journalists have raised the possibility that Russian entities might have used social media around the time of the referendum — known as Brexit — just as the Kremlin was aggressively exploiting Facebook, Twitter and other platforms to try to influence the American presidential election.

Members of Parliament have asked the social media companies for information, fearing that Russia might have tried to undermine confidence in British and European institutions, as it did in the United States. Weakening or dividing the neighboring European Union has long been a priority for Russia, so its use of similar social media tactics to sow discord here has been widely presumed.

But the study, from the Oxford Internet Institute, indicates that evidence is scarce, even taking into account the patterns already disclosed in the United States.