CHARLESTON, W.Va. — The House Oversight Committee on Wednesday subpoenaed Postmaster General Louis DeJoy for records about the widespread mail delivery delays.

The subpoena, which seeks documents related to operational changes that have slowed mail and the agency’s plans for the presidential election, comes after committee leader Rep. Carolyn Maloney said DeJoy has not sufficiently answered the panel’s requests for more information.

He has appeared before Congress twice in recent weeks to testify about the removal of the agency’s blue collection boxes and mail sorting machines, as well as changes to trucking operations and overtime hours that postal workers say are resulting in delays. He has halted some of the changes until after the election.

Separately, an audit by the inspector general of the Postal Service found more than a million mail-in ballots were sent to voters late during the primary elections. The report found state election boards sent more than a million ballots within a week of their primaries, creating a “high risk” that they couldn’t be filled out and returned in time to be counted. In thousands of cases across the country, ballots were sent out after states’ mailing deadlines or on election day.