Deputy Attorney General Rod Rosenstein will testify before the House Judiciary Committee on Dec. 13, Fox News has learned.

The reason for the hearing was not immediately clear.

A source, however, said the hearing is not a standard oversight hearing but rather in response to a specific request made by the committee.

It is expected to be an open hearing.

Rosenstein has oversight over the special counsel's Russia meddling investigation, since Attorney General Jeff Sessions recused himself.

Fox News’ Jake Gibson contributed to this report.