Federal officials say the Congressional bribery investigation now includes Speaker of the House Dennis Hastert, based on information from convicted lobbyists who are now cooperating with the government.

Part of the investigation involves a letter Hastert wrote three years ago, urging the Secretary of the Interior to block a casino on an Indian reservation that would have competed with other tribes.

The other tribes were represented by convicted lobbyist Jack Abramoff who reportedly has provided details of his dealings with Hastert as part of his plea agreement with the government.