The man, who is in his 40s, previously held positions in the party at both the national and local level, but stepped down after he was arrested in 2016.
The politician's defence lawyer Gunhild Lærum told Norwegian broadcaster NRK that she did not yet have a clear response from her client to the charge over the child abuse images.
“We have not yet been able to look through this together,” she said. “He is slightly unsure if this is something he has downloaded consciously and willingly.”
She said the identities of the children in the pictures were “completely unknown”.
The man has been held in pre-trial detention for nearly two years, as police carried out a long-drawn out investigation after finding large quantities of drugs in his house in May 2016.
“We are both pleased at least that something has finally happened in the case,“ Lærum said.
When the police searched the man's house in May 2016, they found 90 grams of amphetamine, 16 grams of cocaine, 19 grams of MDMA, 274 ml of GHB, 22 tablets containing clonazepam, four tablets containing diazepam, five tablets containing MDMA and two tablets containing mCPP.
The man has already pleaded guilty to the drugs charges.
"He has acknowledged that he had a problem and he is glad that it has been discovered and that he has managed to get over it. He has been helped for a long, long period now.”
The case is scheduled to go to trial on September 4.