The increasing presence and use of smartphones threatens to undermine the integrity of the British jury system and "offends the principle of open justice," Dominic Grieve said.
"What does the Internet mean for our system of trial by jury?" he asked. "How can we be sure that jurors decide their cases on the basis of the evidence they hear -- and not what they looked up on their smart phones on the bus on the way to court?"
The challenges posed to the legal system by smartphones and their Internet access are becoming more immediate, he said.
Grieve made his comments in a lecture at the University of Kent on Wednesday, The Guardian reported.
"The Internet is a haystack of material, scattered with the odd prejudicial needle, as it were," he said. "Trial by Google allows a juror to locate the haystack, find the needle, pull it out and ascribe significance to it that it simply would never have had otherwise.
"It takes a minor risk and turns it into a major risk," he said, adding jurors searching the Internet, "offends some foundational principles of our legal system."
"If a jury is exposed to prejudicial material which, for whatever reason, is not before the court, the basis on which the defendant is convicted or acquitted will never be known."