The trial of four members of the billionaire Hinduja family charged with human trafficking over the mistreatment of their domestic staff will proceed in June after judges rejected arguments from their lawyers that the Swiss indictment against them was flawed, according to Bloomberg.

Applications made by lawyers representing Ajay Hinduja, his wife Namrata, his father Prakash, and mother Kamal which were intended to stop or delay the trial from proceeding were rebuffed by presiding Judge Sabina Mascotto on Wednesday in Geneva.

She dismissed several arguments that the defense lacked fair access to troves of evidence on phones and court systems. An attempt to argue the indictment was incomplete and lacking in specific detail was also rejected.

“The charges of usury and human-trafficking were sufficiently well-described by the Prosecutor’s Office and don’t need to be sent back for restating,” Judge Mascotto said.

The indictment alleges that the family made their staff work between 15 to 18 hour days, seven days a week, that their passports were confiscated and that they worked on the basis of short-term tourist visas obtained on false pretenses, over and over again. Their salaries never amounted to more than a few hundred Swiss francs a month, a fraction of local wages, prosecutors allege.

Lawyers for the family previously argued that the charges are based on the prosecutor’s “fantasized” version of events, which contain “serious irregularities and lies.”

Their request for recusal of the presiding Swiss judge over suggestions of bias is still before an appeals court. They have also filed a criminal complaint against “persons unknown” of forgery of documents in the case and abuse of authority, it emerged earlier this month.