London, May 13: Sex beast Josef Fritzl has been branded “Dr. Frankenstein” as medics began tests to determine whether he is mad.

According to the 73-year-old electrical engineer’s lawyer Rudolf Mayer, the incest fiend should not be put on trial as he cannot control his obsessions.

But leading psychiatrist Dr Christian Ludke rejected that claim.

“The criminal energy of this man is unbelievable. He is ice-cold and is still playing power games. We can only separate him from society,” The Sun quoted him, as saying.

Dr Ludke compared Fritzl to the fictional ‘Dr Frankenstein’, who created a monster he thought he could control.

"Fritzl enjoyed being master of life and death. He enjoyed his fantasy of having all the power, he was like Dr Frankenstein,” Dr Ludke said.

Dr Ludke also rubbished Fritzl’s claims that his actions were caused by his strict upbringing during Nazi rule.

The expert said: "He just wants to protect himself and blame someone else."

Fritzl is in jail 50 miles from his home in Amstetten, Austria, where he kept daughter Elisabeth locked up for 24 years. (ANI)