The former spy chief Dennis Richardson has resigned without explanation from the royal commission into antisemitism and the Bondi terror attack, just a fortnight after its opening hearing.

The commissioner, Virginia Bell, released a statement on Wednesday night announcing Richardson’s surprise departure from his role as special adviser to the inquiry.

Expressing “gratitude” for his work, Bell said: “As I noted at the Commission’s initial hearing, Mr Richardson was uniquely well placed to advise on the material to be sought from our intelligence and security agencies in order to assess the effectiveness of their preparedness for, and response to, a terrorist attack.”

The former senior public servant was initially commissioned by the Albanese government to complete a snap review of intelligence agencies after the 14 December terror attack, which killed 15 people and injured dozens more.

_{Sign up: AU Breaking News email}

That work was then folded into the royal commission’s remit after Albanese bowed to weeks of public pressure and agreed to call a wider national inquiry into antisemitism and social cohesion.

Richardson’s examination of the intelligence agencies was designed to inform the commission’s interim report, which was due on 30 April.

In her statement, Bell said work on the interim report was “well advanced”.

She said the other senior members of Richardson’s team, former Asio deputy director-general Tony Sheehan and former defence department deputy secretary Peter Baxter, would remain with the commission to complete the interim report.

Guardian Australian has contacted Richardson for comment.

The royal commission’s final report is due by 14 December 2026.