“employee” means any individual whose pay is disbursed by the Secretary of the Senate or the Chief Administrative Officer of the House of Representatives; and

“court of the United States” has the meaning given it by section 451 of title 28 and includes the United States District Court for the District of the Canal Zone, the District Court of Guam, and the District Court of the Virgin Islands.

as a juror; or

other than as provided in subsection (c) of this section, as a witness on behalf of any party in connection with any judicial proceeding to which the United States, the District of Columbia, or a State or local government is a party;

testify or produce official records on behalf of the United States or the District of Columbia; or

testify in his official capacity or produce official records on behalf of a party other than the United States or the District of Columbia.

If an employee receives an amount (other than travel expenses) for service as a juror or witness during a period in which his pay may not be reduced under subsection (b) of this section, or for which he is performing official duty under subsection (c) of this section, the employee shall remit such amount to the officer who disburses the pay of the employee, which amount shall be covered into the general fund of the Treasury as miscellaneous receipts.

An employee summoned (and authorized to respond to such summons by the House of the Congress disbursing his pay), or assigned by such House, to testify or produce official records on behalf of the United States is entitled to travel expenses. If the case involves an activity in connection with which he is employed, the travel expenses shall be paid from funds otherwise available for the payment of travel expenses of such House in accordance with travel regulations of that House. If the case does not involve such an activity, the department, agency, or independent establishment of the United States on whose behalf he is so testifying or producing records shall pay to the employee his travel expenses out of appropriations otherwise available, and in accordance with regulation applicable, to that department, agency, or independent establishment for the payment of travel expenses.

An employee summoned (and permitted to respond to such summons by the House of the Congress disbursing his pay), or assigned by such House, to testify in his official capacity or produce official records on behalf of a party other than the United States, is entitled to travel expenses, unless any travel expenses are paid to the employee for his appearance by the court, authority, or party which caused him to be summoned.