An Iraqi court has sentenced a British citizen to 15 years in prison on charges of smuggling artefacts out of the country.

The verdict handed down to retired geologist Jim Fitton shocked the court in Baghdad, including his defence lawyer.

He and his family have argued that Fitton, 66, had no criminal intent.

A German national tried with Fitton was found not to have criminal intent in the case and will be released.

"I thought the worst-case scenario would be one year, with suspension," Fitton's lawyer Thair Soud, visibly shocked, told the Associated Press.

Judge Jabir Abd Jabir found that by picking up the items, found to be artefacts dating older than 200 years according to a technical government investigation, and intending to transport them out of the country, Fitton had criminal intent to smuggle them.

The judge did not consider Fitton's lawyer's arguments that laid out Fitton's ignorance of Iraqi laws and the value of the items he picked up.

Fitton and the German national, Volker Waldman, were arrested in Baghdad airport on March 20 after airport security discovered the items in their luggage.

They had been part of a tourism expedition across the country's ancient sites.

Fitton's family grew worried when he did not arrive on a scheduled flight back to Kuala Lumpur, where he resides with his wife, on March 20.

They later learned that Fitton, a well-travelled geologist for oil and gas companies, had been taken to an airport holding cell, Fitton's daughter Leila told AP last month.

The case garnered attention when, frustrated by perceived inaction on the part of the British Foreign Office to intervene and assist in Fitton's case, his family started a petition that has garnered more than 100,000 signatures.

The British diplomatic mission in Baghdad has not commented on its involvement in the case.

In total, 12 fragments of pottery and other shards were found in Fitton's possession by Iraqi authorities, all of them collected as souvenirs, Fitton's family says, during a group tourism expedition to Eridu, an ancient Mesopotamian site in what is now Dhi Qar province.

Mr Waldman's defence team has said the German tourist had been carrying the pieces for Fitton but that he did not pick them up from the site.

Fitton's lawyer said he intends to appeal the sentence immediately. It is not clear if Fitton can serve out his sentence in his home country, this would require a bilateral agreement between Iraq and the UK.