**Exhibit 99.6**

 
|        |                             |
|--------|----------------------------------|
|   | Deloitte &   Touche LLP |
|   | Brookfield   Place               |
|   | 181 Bay   Street                 |
|   | Suite 1400                  |
|   | Toronto, ON   M5J 2V1            |
|   | Canada                           |
|   |                             |
|   | Tel:   416-601-6150              |
|   | Fax:   416-601-6610              |
|   | www.deloitte.ca                  |

 

**Report of Independent Registered Chartered Accountants**

 

To the Shareholders and Board of Directors of HudBay Minerals Inc.

 

We have audited the internal control over financial reporting of HudBay Minerals Inc.****and subsidiaries (the “Company”)****as of December 31, 2011, based on the criteria established in *Internal Control—Integrated Framework* issued by the Committee of Sponsoring Organizations of the Treadway Commission. The Company’s management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting, included in the accompanying Management’s Report on Internal Control over Financial Reporting. Our responsibility is to express an opinion on the Company’s internal control over financial reporting based on our audit.

 

We conducted our audit in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects. Our audit included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, testing and evaluating the design and operating effectiveness of internal control based on the assessed risk, and performing such other procedures as we considered necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinion.

 

A company’s internal control over financial reporting is a process designed by, or under the supervision of, the company’s principal executive and principal financial officers, or persons performing similar functions, and effected by the company’s board of directors, management, and other personnel to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company’s internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

 

Because of the inherent limitations of internal control over financial reporting, including the possibility of collusion or improper management override of controls, material misstatements due to error or fraud may not be prevented or detected on a timely basis. Also, projections of any evaluation of the effectiveness of the internal control over financial reporting to future periods are subject to the risk that the controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

 

 

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In our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2011, based on the criteria established in *Internal Control — Integrated Framework*issued by the Committee of Sponsoring Organizations of the Treadway Commission.

 

We have also audited, in accordance with Canadian generally accepted auditing standards and the standards of the Public Company Accounting Oversight Board (United States), the consolidated financial statements as of and for the year ended December 31, 2011 of the Company and our report dated March 7, 2012 expressed an unqualified opinion on those financial statements.

 

 
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|----------------------------------------------|--------|
|                                         |   |
| Independent Registered Chartered Accountants |   |
| Licensed Public Accountants                  |   |
|                                         |   |
| March 7, 2012                           |   |
| Toronto, Canada                              |   |

 

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