The Department of Energy and Climate Change spent more than £300,000 on artificially boosting its Google rankings in the last financial year, according to figures released by the government.
The department did not reveal which web pages or services were marketed using the method.
Minister Gregory Barker revealed £309,8000 plus VAT was allocated to paid search in the 2009-10 financial year.
The figures were revealed in response to a written parliamentary question from Tory MP Damian Hinds, who asked how much the department spent on "search engine biasing" with Google and other search engines.
Barker also revealed that the department's support for low-carbon technology and helping businesses migrate to cleaner methods of working has been but by £34m in the 2010-11 budget.