After FBI agents were briefed yesterday, they concluded the security company offering the alternate theory did not have an accurate understanding of all the evidence, a U.S. official familiar with the matter told POLITICO today.

The three-hour meeting with FBI investigators yesterday by cyber intelligence firm Norse “did not improve the knowledge of the investigation,” according to the U.S. official.

Investigators are open to new information brought forth by researchers, the official said, but it became clear in the meeting yesterday that Norse’s evidence was “narrow” and not an accurate analysis of the information, the official said.

Norse had said it found evidence pointing to a disgruntled employee as the source of the Sony hack and offered the research to the FBI, which scheduled the meeting. When asked about the briefing yesterday, the FBI released a short generic statement saying it was standing by its earlier assessment that the North Korean government was responsible for the crippling attack on Sony and there was “no credible information” to suggest otherwise.

Since the FBI released a statement earlier this month that the North Korean government was behind the attack, some security experts have questioned the evidence they cited as thin. Officials say the government’s investigation has collected evidence from a variety of sources and not all of it has been released.