States Services Commissioner Iain Rennie says no other complaints were made about Cera boss Roger Sutton during a seven-week investigation.
Mr Sutton resigned yesterday after a complaint that he harassed a senior female staff member by giving hugs and making inappropriate jokes and comments.
Mr Rennie would not confirm to Campbell Live that the complaint had been corroborated, but said evidence from witnesses helped the investigation into an allegation of sexual harassment.
"The bulk of the complaint has been upheld, the behaviour was of serious misconduct," he said.
Mr Rennie said he had contacted the complainant yesterday.
"I apologised to her for her treatment. It caused her genuine hurt and distress and she should not have been treated in that way. I also thanked her for her courage, her courage to come forward and complain. That is not easy but that is the only way that we can take action on these concerns."
Mr Rennie said employment law prevented him from divulging the details of the complaint.
Mr Sutton walked in to a press conference hand-in-hand with wife Jo Malcolm yesterday to announce his resignation, of his "own free choice", effective from January 31 next year.
"Hugs, jokes ... I do do those things, and I've hurt somebody with that behaviour and I'm very, very sorry about that," Mr Sutton said.
"But I am who I am. I have called women 'honey' and 'sweetie', and that is wrong. That's a sexist thing to do, and I'm really sorry."
His wife said the investigation process had been "hideous", and her husband's "hugs and jokes have been misinterpreted".