A Russian dissident accused of making and possessing thousands of indecent photographs of children said he was doing research and that some of those involved looked to be enjoying themselves, a court has heard.
Vladimir Bukovsky, who sat in court in a wheelchair, has gone on trial accused of having accessed still and video images over 15 years, some of which were being downloaded at the point of his arrest in 2014.
The 73-year-old told police he had become curious at the end of the 1990s about issues involving control of and censorship of the Internet and decided to look into what was available online, prosecutor Will Carter said.
The pensioner, who was living alone in Cambridge when he was arrested, said it had become something of a hobby, which he told no-one else about.
Mr Carter said: "What he said was that his initial curiosity turned into a hobby rather like stamp-collecting."
Bukovsky denies five counts of making indecent images of children, five of possessing indecent images of children and one of possessing a prohibited image of a child.
Opening the prosecution case to the jury of eight men and four women at Cambridge Crown Court, Mr Carter said Bukovsky had told police that he considered he was not harming anyone or committing any crime by looking at the images.
Mr Carter said some of the material found on hard drives at the defendant's home involved children of toddler age. Bukovsky told police the youngest were six or seven.
Mr Carter said: "He said he wouldn't download any which showed a toddler although he said age could be difficult to judge."
The barrister said Bukovsky had noted that "they (those in the images) looked to him as if they were enjoying themselves".
Russian-born Bukovsky - an author and activist who became well-known internationally as a vocal critic of the Soviet regime - returned to the UK from Germany to face the charges. He had been receiving private medical treatment abroad.
A handful of his supporters were in court.
The defendant is considered a hero by some who support democratic reform in Russia, but has another side, the jury was told.
Mr Carter said: "The prosecution say that there was another side to this man which was far from laudable, an extensive interest in real children really being abused."
The trial continues.
The trial was adjourned until Tuesday at 10.30am.