(CNN) Michael Flynn's lawyers have told other defense lawyers in the ongoing Russia probe, including President Donald Trump's legal team, that they're no longer able to share information, a source familiar with the matter told CNN.

The source added that the decision to cease informal information-sharing could be an indication Flynn is preparing to plead guilty in Special Counsel Robert Mueller's investigation.

The New York Times first reported the change Thursday, citing four people involved with the case, and added that it could be "an indication that Mr. Flynn is cooperating with prosecutors or negotiating ... a deal."

While Flynn's lawyers had previously shared information with Trump's team, the change does not necessarily indicate that Flynn is cooperating with Mueller.

Jay Sekulow, a member of Trump's legal team, said that the decision to no longer share information "is not entirely unexpected" and shouldn't be seen as an indication of cooperation.

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