Australian engineer Robert Pether has been in Iraq's prison cell for more than four years after he was arbitrary detention.

Pether was building a new headquarters for the Iraqi Central Bank when he was detained in Baghdad in April 2021 to help establish a new headquarters.

He has met with bank officials to resolve disputes about CME Consulting, an engineering company related to the project.

Pether was later sentenced and fined and accused his company of spending money to be handed over to architects and subcontractors.

In a report in March 2022, the United Nations' arbitrary detention task force found that Pther was arbitrary detained in violation of international law.

It also heard allegations that the trial of Pess and his Egyptian colleagues was damaged and that he was subjected to a similar to torture. The bodies demanded that they be released immediately and unconditionally.

After more than four years in prison, Pether has now been released.

Pether’s wife Desree welcomed the development and said her family “thank you to everyone who contributed to this.”

But she also warned her husband that he was trapped in Iraq due to the ban and needed medical services in a desperate need.

"He couldn't identify it," she told the Australian Guardian. "So fragile and weak. He needs emergency medical treatment, which is impossible in Iraq."

Foreign Minister Penny Wong said the Australian government has filed more than 200 cases with Iraqi authorities.

"I would like to thank Australian officials for their unremitting efforts in the Mr. Pess case, including Australia's special envoys who have traveled to Iraq in recent weeks to negotiate the outcome," she said.

The case prompted the Prime Minister to intervene, and Anthony Albanese detained Pether in 2022 with then-Iraq Prime Minister Mustafa al-Kadhimi.

In 2022, Guardian received an emotional letter from Pether to his family and wrote it from his cell. The letter warned his family that his prognosis was “bleak” and that he was facing a potential “death penalty.”

Pether also wrote about his daily torture, saying how he should break down the kids he might not go home.

Pesser wrote: "How do you tell a little girl who loves unicorns and cats that her dad won't come home? How do you tell the kids that you are proud of them but not share their honors (and traps) with them?"

“The hardest thing is, how do you tell your wife that it’s very hard for you to keep the promise that you will age?”