One of six Christian ministries under investigation by a Senate committee is rebuffing inquiries into its spending, challenging the panel’s watchdog role over religious groups, The Associated Press has learned.

A lawyer for preacher Creflo Dollar of World Changers Church International in suburban Atlanta has asked Sen. Charles Grassley to either refer the matter to the IRS or get a subpoena, according to a letter from Dollar’s attorney obtained Wednesday by the AP.

Grassley, the ranking member of the Senate Finance Committee, sent pointed questionnaires in early November to a half-dozen ministries, asking about salaries, perks, travel and oversight. The Iowa Republican set today as the deadline for a response.

All six organizations preach a form of the “prosperity gospel,” the belief that God wants his faithful followers to reap material rewards.

Besides Dollar, several other televangelists have signaled concerns about invasions of privacy and violations of religious freedom. Only Joyce Meyer Ministries of Fenton, Mo., has provided the detailed financial and board oversight information sought by Grassley.

Aside from Dollar and Meyer, the other televangelists who received letters from Grassley are Bishop Eddie Long, who leads a megachurch and ministry in Lithonia, Ga.; Randy and Paula White of Without Walls International Church and Paula White Ministries of Tampa, Fla.; Benny Hinn of World Healing Center Church Inc. and Benny Hinn Ministries of Grapevine, Texas; and Kenneth and Gloria Copeland of Kenneth Copeland Ministries of Newark, Texas.