Best known for his role in "Janus", a 1990s ABC television series, Melbourne actor Jeremy Kewley on Wednesday has pleaded guilty to 19 child sex offences committed against boys as young as nine, indecent assault and making and possessing child pornography at the County Court of Victoria.

The former "Neighbours" star, who was first charged in December, sexually assaulted 16 young boys, forcing them to wear tight Lycra costumes, and inviting them to his home for 'screen tests', the court heard, local media reported.

According to the prosecutors, Kewley filmed the boys and touched them inappropriately while he wrestled, strangled and kissed them.

Kewley, who allegedly sexually assaulted his first victim in 1989, said that he wanted the 13-year-old boy to audition for an advertisement after first meeting him on the set of "Young Talent Time".

Over several days, he had 12 boys attend his home in Brighton to perform screen tests for a movie, "Malevolence", in June and July of 2011, where he sexually assaulted them as he acted alongside the boys while the camera was running, the Daily Mail reported.

The parents of the boys were asked to wait downstairs for the screen tests, Crown prosecutor Nanette Rogers told the court. The said movie has been released as a small-budget film, reports say the court heard.

Images and videos containing child pornography were also found on Kewley's computer hard drives when the police raided his properties a couple of years ago, the court heard. He is also guilty to two charges of producing child pornography and a single count of possessing child pornography.

Defense barrister Con Heliotis QC told the court they were opportunistic crimes.

“He believed he could get away with this because his victims would think it was all part of the script,” he said.