Opera singer David Edward Lewis has pleaded guilty to historic child sex offenses, the Sydney Morning Herald has reported. The tenor, who was a permanent member of the Opera Australia Chorus for 25 years, was charged with four counts of aggravated indecent assault of a victim under the age of 16, two counts of sexual intercourse with a person 14 or over and under 16, and one count of committing an act of indecency with or towards a person under 16. Lewis pleaded guilty to all but one of the charges at Downing Centre Local Court on Thursday. One charge of aggravated indecent assault was withdrawn.

Lewis, who performed most recently in last year’s Two Weddings, One Bride, notified Opera Australia in July last year that charges had been brought against him, subsequently taking long service leave before tendering his resignation in October. “Opera Australia was made aware of these allegations in July 2017,” Opera Australia CEO Rory Jeffes said in an official statement issued to staff in November when the charges were made public. “Due to the nature of the charges Opera Australia took immediate action to stand David Lewis down and require that he stay away from the workplace. He has not participated in any company activity since then and he is no longer an employee of Opera Australia.”

The Sydney Morning Herald reported that the victim, who was 14 years old at the time the offences occurred in the mid 1990s, when she was a member of the children’s chorus of an Opera Australia production, came forward after Lewis appeared as the Emperor in the 2016 production of Turandot on Sydney Harbour.

According to the Sydney Morning Herald, sources told Fairfax Media last year that one assault was witnessed by a cast member who reported it to senior figures within Opera Australia, who then appointed a chaperone for the children. “Opera Australia has cooperated fully with the police authorities since they approached the Company and will continue to do so,” Jeffes said at the time, saying that there was “no record of any allegations of this nature against David Lewis being reported to Opera Australia as suggested in the article.”

The court case comes as arts organisations are under increasing scrutiny over responses to allegations of sexual harassment and inappropriate behaviour in the workplace, with the major subsidised theatre companies signing up for a high-level forum on sexual harassment following last year’s Media Entertainment and Arts Alliance survey on sexual harassment and bullying in live performance. The forum will not include commercial theatre, opera or dance companies.

“Opera Australia continually revises its procedures, polices and processes relating to staff safety and wellbeing,” Jeffes said last year. “It is worth stating that Opera Australia complies with all requirements and recommendations of the Children’s Employment Authorities and has robust and comprehensive procedures in place to ensure the safety of all underage artists appearing with the company.”

Lewis will be sentenced later this year, with the matter listed for a hearing in the District Court on March 23.