Vienna   - A security guard was injured by a photographer on Monday at the Amstetten-Mauer neuro-psychiatric clinic, where Austrian incest victims Elisabeth Fritzl and her family are in therapy at the same time that the paparazzi hunt for photos intensifies.

The guard, who was pursuing a paparazzo who had illegally entered the clinic grounds, was hit with a truncheon and was being treated in hospital, a clinic spokesman confirmed.

"This was the worst incident of this kind," spokesman Klaus Schwertner said.

Photographers were constantly trying to get access to the family, he said, taking taking increasingly extreme measures to shoot the first photos of Elisabeth, 42, and five of her children who are also being treated at the clinic.

"The clinic grounds a very spacious, we are always apprehending some individuals," he said. Up to now there had been "problems with about 20" photographers, who had to be removed from the grounds, Schwertner added.

Photos of the Amstetten incest victims are believed to fetch more than 1 million dollars, Austrian media said.

Only last weekend another guard was injured in a scuffle with a photographer who attempted to scale the balcony of the Fritzl family's ward.

Elisabeth was imprisoned and sexually abused by her father, Josef, 73, for 24 years, and gave birth to six surviving children during her captivity.

She, her mother, and five of the children have received treatment and are slowly learning to readapt to a normal at the Amstetten-Mauer clinic since the shocking crime was uncovered last month.

Doctors have been constantly appealing to the media to respect the family's privacy in order as to not endanger their healing process, a request that is falling increasingly on deaf ears.

The family's lawyer on Sunday refuted media reports that Elisabeth was considering an interview with Austrian public broadcaster ORF. There would be "no interviews for the time being," lawyer Christoph Herbst made clear. (dpa)