"There are data about the significant increase in the online traffic a year ago, at the height of the Catalan crisis, from servers located in Russia and Venezuela. But I cannot bring charges against the Russian government without any evidence," Borrell told La Vanguardia newspaper.
The crisis in Catalonia escalated last fall after the region held an independence referendum on October 1, 2017, while Madrid refused to recognize the voting and regards it as illegal.
READ MORE: Lavrov Trolls Spain at UN, Says Russia 'Busy Meddling in Catalonia's Elections'
A number of Spanish media, including El Pais newspaper, published last year a set of articles about the Russian media's allegedly biased coverage of the situation in Catalonia and about the support of separatists by "Russian hackers."
In response to the minister’s remarks, Russian Foreign Ministry’s spokeswoman Maria Zakharova called on Madrid to provide specific evidence of Moscow’s alleged interference in the situation in Catalonia. No official response has been provided yet.