Derbyshire County Council's pension fund invests more than £140million in fracking firms, it has emerged.
Statistics show the Derbyshire Pension Fund has pumped a total of £257m into fossil fuel companies.
Of that figure, £143m is invested with businesses including Shell, BP and Newfield Exploration, which have major fracking operations around the globe.
The Derbyshire Times has obtained the controversial data from green campaign groups 350.org, Platform, Energy Democracy Project and Friends of the Earth, which uncovered the statistics using the Freedom of Information Act.
Divest Derbyshire - which is made up of 20 environmental organisations across the county - believes the investments threaten the climate.
The county council insists it is responsible for ensuring the fund has enough money to pay members' pensions and stresses it gives 'due consideration to the issue of climate change'.
Currently, the county council is considering a planning application by fracking firm INEOS to explore shale gas reserves off Bramleymoor Lane, between Marsh Lane and Apperknowle, near Eckington.
The authority is yet to make a decision on the contentious proposal.
According to the figures, the county council does not invest in INEOS.
Dave Kesteven, chairman of Eckington Against Fracking, said: "While many Derbyshire residents are actively campaigning to stop fracking, it adds insult to injury that our own county council is supporting fracking through its investments."
James Eaden, president of Chesterfield and District Trades Union Council, said: "We need investment in a sustainable economy which promotes green jobs and technology.
"Local councils should take the lead in this by making sure that the huge funds they hold in pension funds on behalf of present and past employees are used in an environmentally responsible way."
Michelle Cadet-Rose, a member of the Derbyshire Pension Fund, said: "We want our pension fund invested in more forward-thinking and sustainable industries."
Hilary Hebron, of Transition Wirksworth Activists, added: "It is extremely urgent that we stop using fossil fuels now."
A county council spokesman said: "As the administering authority for the Derbyshire Pension Fund, Derbyshire County Council has a responsibility to ensure that there are sufficient funds to pay our members' pensions when they are due.
"However, we do give due consideration to the issue of climate change as part of our evaluation of all investment risks associated with the fund’s diverse portfolio, which has a total current value of £4.6billion. The proportion of investment in companies directly and indirectly involved in the production of fossil fuels accounts for around five per cent of the total portfolio.
"Our Pensions and Investments Committee is open to representations about how we invest our members' money. In fact, we recently received a comprehensive report on the issues of climate change and fossil fuel investments, which is available to read on the council's website, following representations made by Transition Chesterfield.
"As part of our duty to invest our members' contributions responsibly, we are committed to a policy of engagement with all companies in the fund’s portfolio through the Local Authority Pension Fund Forum, which aims to encourage business to adopt strategies which help to address the issue of climate change."
The county council manages the Derbyshire Pension Fund on behalf of 190 local employers, including Derby City Council and all the district and borough councils in the county.
There are 90,000 pension scheme members.
According to the figures, local councils across the UK have £16.1bn of their workers' pensions invested in fossil fuel companies.