Speaking in parliament two days after the deadly shooting, Alfano said Italy was aware of one of the suspects’ links to extremism in Iraq.
“One of the killers in Paris was known to Italian police,” he said. “But he was never in the national territory.”
France on Thursday named two Parisian brothers - Cherif and Said Kouachi - as the chief suspects in the Paris killing spree. Alfano did not specify which of the brothers was known to Italian authorities.
Cherif, 32, was in 2008 jailed in France for helping send jihadists to fight for terrorist organization al-Qaeda in Iraq.
He was also linked to a former member of the Algerian Armed Islamic Group (GIA), which carried out a series of attacks in France in the 1990s, and suspected of attending military training with French jihadist Djamel Beghal.
Less is known about 34-year-old Said, who along with his brother was still at large on Friday morning. The duo was thought to have been aided in the attack by 18-year-old Mourad Hamyd, who has handed himself into police in France.
In response to the Charlie Hebdo killings - described by Alfano as a “cruel attack against democratic values” - Italy plans to implement a new law against would-be jihadists.
Fresh legislation will target “foreign fighters” who seek to travel from or through Italy en route to join Islamic fundamentalists. The intention is to “restrict their ability to go into the field”, the interior minister said, with the new law enabling the Italian government to take away suspects’ passports.
Italian intelligence has already pinpointed 53 foreign fighters who have departed from or transited through the country.
Alfano also drew on the dangers of “homemade” terrorism and web radicalization, saying Italy needed greater access to conversations between extremists online.
Help is needed from the world’s largest internet companies to give the Italian government access to such data, creating a “black list” of those who pose a security threat.
Alfano’s proposal will likely raise alarm bells among those opposed to governments encroaching on people’s online privacy in the name of national security.
The threat posed by extremist groups was identified as the greatest danger to Europe during Italy’s recent EU presidency, Alfano said.
Combatting terrorism needs a “spirit of unity” within the EU and international cooperation, said the interior minister, ahead of a top-level meeting in Paris on Sunday.
Alfano will be joined by his EU counterparts and US representatives for the anti-terrorism talks, which he said “represent a symbolic moment to show support for France” following this week’s attack.