Federal investigators are examining whether the emails allegedly describing activities by Joe Biden and his son Hunter and found on a laptop at a Delaware repair shop are linked to a foreign intelligence operation, two people familiar with the matter told NBC News.

The FBI seized the laptop and a hard drive through a grand jury subpoena. The subpoena was later published by the New York Post. The bureau has declined to comment.

The Post, a conservative tabloid, has published a series of stories based on emails the newspaper said it obtained from President Donald Trump’s attorney, Rudy Giuliani. The first story highlighted what it called a “smoking gun email” that suggested a meeting between Vice President Biden and a representative of a Ukrainian company that once paid Hunter Biden. The Biden campaign says there is no evidence the meeting happened, and the story was greeted with widespread skepticism.

George Mesires, attorney for Hunter Biden, said in a statement, “We have no idea where this came from, and certainly cannot credit anything that Rudy Giuliani provided to the New York Post, but what I do know for certain is that this purported meeting never happened.”