Which Ministry/Department controls the CVC?

The CVC is not controlled by any Ministry/Department. It is an independent body which is only responsible for the Parliament.
Powers and Functions as per the CVC Ordinance1998, which was in existence till 7th January 1999.

Functions & Powers of CVC

8. (1) The functions and powers of the Commission shall be to- (a) exercise superintendence over the functioning of the Delhi Special Police Establishment insofar as it relates to the investigation of offences alleged to have been committed under the Prevention of Corruption Act, 1988; (b) inquire or cause an inquiry or investigation to be made on a reference made by the Central Government wherein it is alleged that a public servant being an employee of the Central Government or a corporation established by or under any Central Act, Government company, society and any local authority owned or controlled by that Government, has committed an offence under the Prevention of Corruption Act, 1988; (c) inquire or cause an inquiry or investigation to be made into any complaint against any official belonging to such category of officials specified in sub-section (2) wherein it is alleged that he has committed an offence under the Prevention of Corruption Act, 1988; (d) grant approval or otherwise for the conduct of investigation into allegations of corruption under the Prevention of Corruption Act, 1988 against the persons mentioned in section 6A of the Delhi Special Police Establishment Act,1946 in accordance with the regulations made in this behalf; (e) review the progress of investigations conducted by the Delhi Special Police Establishment into offences alleged to have been committed under the Prevention of Corruption Act, 1988;
(f) review the progress of applications pending with the competent authorities for sanction of prosecution under the Prevention of Corruption Act, 1988; (g) tender advice to the Central Government, corporations established by or under any Central Act, Government companies, societies and local authorities owned or controlled by the Central Government on such matters as may be referred to it by that Government, said Government companies, societies and local authorities owned or controlled by the Central Government or otherwise; (h) exercise superintendence over the vigilance administration of the various Ministries of the Central Government or corporations established by or under any Central Act, Government companies, societies and local authorities owned or controlled by that Government.

(2) The persons referred to in clause (c) of sub-section (1) are as follows:- Group `A’ officers of the Central Government; such level of officers of the corporations established by or under any Central Act, Government companies, societies and other local authorities, owned or controlled by the Central Government, as that Government may, by notification in the Official Gazette, specify in this behalf: Provided that till such time a notification is issued under this clause, all officers of the said corporations, companies, societies and local authorities shall be deemed to be the persons referred to in clause (c) of sub-section (1).

9. (1) The proceedings of the Commission shall be conducted at its headquarters.
(2) The Commission shall observe such rules of procedure in regard to the transaction of the business as may be provided by regulations. (3) The Central Vigilance Commissioner, or, if for any reason he is unable to attend any meeting of the Commission, the seniormost Vigilance Commissioner present at the meeting, shall preside at the meeting.
(4) No act or proceeding of the Commission shall be invalid merely by reason of-

• any vacancy in, or any defect in the constitution of, the Commission; or
• any defect in the appointment of a person acting as the Central Vigilance Commissioner or as a Vigilance Commissioner; or
• any irregularity in the procedure of the Commission not affecting the merits of the case.