My fracking study was fully independent, says professor - as campaigners say universities have been hijacked by PR machine

The lead author of a report which compared seismic activity caused by fracking to the energy produced by someone jumping off a ladder insisted today that his study was fully independent of big energy companies.

Professor Richard Davies of Durham University, who has previously worked in exploration for ExxonMobil, said it was vital that academics in the field had direct experience in the industry.

The study found that only three earthquakes able to be detected by humans had been caused by fracking in which shale rock is blasted with water, sand and chemicals, despite the drilling of hundreds of thousands of wells since 1929.

But campaign group Frack Off claimed that the peer-reviewed study published in the journal Marine and Petroleum Geology today demonstrated that universities had been "hijacked by the industry PR machine" mirroring the so-called "fracademia" row in the United States.

The Durham Energy Institute, of which Professor Davies is director, boasts a number of private partners from the energy sector including the part Chinese-state owned IGas which has raised £23.1m to fund exploration for shale gas in North West England this summer. The company also owns licences to drill in the Chancellor George Osborne's constituency of Tatton.

Hydraulic fracturing (fracking) operations to recover shale gas in Lancashire were suspended in 2011 after two minor earthquakes. The Government has lifted the moratorium on the process and is backing further exploration of on-shore shale gas reserves to help plug Britain's growing energy gap.

Professor Davies said the paper was funded by his university and said in the past he had confronted oil companies over drilling activities which he argued led to the eruption of a mud volcano in Indonesia in 2006 and the displacement of 30,000 people.

He said: "I think it is critical we have people who know about the oil and gas industry. We rely on the data from the industry. We do need to be close to the coalface to understand what's going on."

He added: "It is incredibly difficult to get experts to work on things who have no previous direct first-hand experience with the technology or the industry."

Professor Davies said he was "agnostic" over the technology and warned over the long-term integrity of wells and the impact of road traffic on communities affecting by fracking operations.

Charlotte Wilson of Frack Off said: "Claiming that there was no direct industry funding is just accounting trickery. If the people involved are receiving large amounts of money from the industry it doesn't matter what it is claimed to be for, it totally undermines their credibility."