Story highlights Comey was concerned that the allegation would make the FBI look bad

FBI officials reached out to DOJ personnel to try to clear up the reports

(CNN) FBI Director James Comey was "incredulous" over the weekend after President Donald Trump's allegation via Twitter that former President Barack Obama ordered a wiretap of his phones during the campaign, a person familiar with the matter told CNN.

The source said Comey was concerned that the allegation would make the FBI look bad, and that concern was part of what prompted the FBI director to have his staff reach out to staff at the Justice Department asking them to knock down the allegation.

The source said Comey felt "institutionally he has to push back on this" because the magnitude of the allegations that Comey knows not to be true.

Over the weekend, senior-level officials within the FBI reached out to career personnel at the Justice Department to try to clear up reports that Obama wire-tapped Trump's phone, a US official told CNN. Part of the discussion was the FBI asking for DOJ to publicly knock down the allegations, which so far DOJ has not done.

Comey was aware of those discussions, the US official said, but Comey himself did not reach out to DOJ over the weekend.

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