Chancellor Angela Merkel on Wednesday expressed caution over whether the revolutionary oil and gas technique of "fracking" could be introduced in Germany, saying public safety was the main concern.

The technology of "hydraulic fracturing", which has unlocked immense gas and oil resources and changed the geopolitics of energy, would "very probably also open up new gas deposits in Germany," Merkel told the Straubinger Tagblatt.

"Contrary to large parts of the United States, we are living here in a very densely populated country," Merkel told the regional daily in an interview.

The technology, also called "unconventional" production, remains highly controversial, with widespread, serious worries for the environment and the health of people living near the "fracking" locations.

It has been banned in France since 2011 but German Environment Minister Peter Altmaier promised at the weekend to introduce legislation on the topic before federal elections on September 22.

"We have to look very carefully as to whether this technology can be used here as well. For me, the most important thing is that there should be no danger to people or the environment," insisted the chancellor.

She vowed a "dialogue" between companies, politicians and citizens before any major decisions were taken on the use of the technique in Germany.

Since its invention in 2007, "fracking" has become the gold rush of the 21st century, with tens of billions of dollars in revenue and hundreds of thousands of new jobs.