Empty chairs at an otherwise routine inquiry into the passage of religious hate laws sparked a threat that staff for NSW Premier Chris Minns and Police Minister Yasmin Catley could be arrested.
Committee chair Rod Roberts says the five staffers will now appear.
"That's the undertaking they've given us," the independent MP told Sydney radio 2GB on Wednesday.
It came after upper house president Ben Franklin sought legal advice from eminent barrister Bret Walker SC, which affirmed the house was within its rights to seek arrest warrants for the staffers failing to appear.
The premier and minister, as members of parliament's lower house, cannot be compelled to appear.
The inquiry was formed to probe the passage of protest and speech laws rushed through parliament in February after explosives, anti-Semitic messaging and a list of addresses of Jewish people and institutions were found inside a caravan at Dural in Sydney's northwest in January.
Investigators later revealed the discovery was part of a "criminal con job".
Committee member Sue Higginson said the committee had powers to compel attendance under threat of arrest.
"They are written in black and white in the parliamentary evidence act in no uncertain terms," she told ABC radio.
"No person in NSW is above the law, a summons duly issued means that an individual must comply with that."
The premier's chief of staff James Cullen, deputy Edward Ovadia and staffer Sarah Michael were summoned to appear, along with Ms Catley's chief of staff Ross Neilson and deputy Tilly South.
"They were present in meetings and briefings that the inquiry is concerned with," Ms Higginson said.
"We believe these individuals hold information that could genuinely assist us in exercising our forensic capacity."
The staffers are expected to appear before the inquiry on Friday.
