Exhibit 23.1 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the incorporation by reference in Registration Statement No. 33-38429 of Magellan Petroleum Corporation on Form S-8 of our report dated October 13, 2004 appearing in this Annual Report on Form 10-K of Magellan Petroleum Corporation for the year ended June 30, 2004. /s/ Deloitte & Touche LLP Hartford, Connecticut October 13, 2004