MADISON, Wis. (AP) — Republican Gov. Scott Walker isn't saying much about FBI Director James Comey's testimony that the bureau has been probing links between President Donald Trump and Russian officials.

Comey said during a congressional hearing Monday that the investigation began last July. He also rejected Trump's claims that former President Barack Obama had wiretapped his New York skyscraper.

Walker told reporters during a question-and-answer session Monday at the state Capitol that he hadn't seen Comey's testimony and isn't privy to any more information than the general public. He said he believes the wiretapping allegations and suspicions of Russian collusion are serious issues and should be reviewed.

Asked if he thought Trump should apologize for the wiretap allegations, Walker said he'd leave that up to people with "firsthand knowledge of the situation."