Robert Hughes was an unpopular person among his colleagues. He was also the only cast member to have his own dressing room, which the other actors occasionally used. As a child, Sarah Monahan proudly told her close castmates of how she had urinated in Robert's shampoo bottle while he was out of the room, "so he could wash with it". She had also squashed mulberries all over his brand-new white car.
In March 2010, detectives from the Sex Crimes Squad of the New South Wales Police formed Strike Force Ruskin, to investigate allegations of sexual abuse on the set of the show. In 2012, it was reported that over 200 witnesses; including cast and crew and their friends, relatives, and acquaintances had been interviewed as part of the investigation process. In May 2012, detectives applied for, and were granted, an arrest warrant for a 63-year-old man. Since then, detectives conducted extensive inquiries internationally to locate the man, including with the London Metropolitan Police. On August 8th, 2012, Robert Hughes was arrested in London, England, and charged with 11 offences against five girls between 1985 and 1990. Robert Hughes has always publicly denied the charges. The case went to trial in early 2014 and resulted in Hughes being found guilty of 10 of the charges. He was sentenced to a prison term of a maximum of 10 years and nine months, or a minimum term of six years, after which he could apply for parole. In June 2022, Hughes was granted parole on his third application, allowing him to be deported to the United Kingdom, after he had renounced his Australian citizenship. Sarah Monahan was again present for Robert's court appearance, stating to media that she was no longer afraid of him. Upon his return to the UK and release, Hughes is required to check in with police once a year.
During the show's original run, the young female cast members Simone Buchanan and Sarah Monahan often had problems with obsessive fans following them around; in Sarah's case, a stalker would send roses to her school when she was only 10.
When Robert Hughes recorded his final episode, cast and crew had planned a farewell party for him, but were unable to find him after the show, as he had left the studio immediately after taping his final scene. A former cast member in attendance at that party stated that for Robert to attend would have been too awkward, with all the rumours that were going around among cast and crew about his backstage behaviour.
When Brisbane radio station B105 organised a "Hey Dad..!" reunion in September 2009, nearly all of the cast members refused to take part once they found out that Robert Hughes would be involved. To ensure that the reunion proceeded with the majority of the cast, Robert was dropped from the reunion and the part of Martin in the scripted scenes was played by radio host Stav Davidson.