A family of 17 suspected Uighur Muslims at the centre of a diplomatic tug-of-war between Turkey and China will remain in custody until their nationalities are proven after a Thai court has rejected their argument that their prolonged detention was illegal.

The court ruled on Friday that Thai immigration had the right to detain the group but made no ruling on their nationality.

Turkey and China both claim the detainees as nationals in a dispute with potential implications for hundreds of other suspected Uighur detainees and to where they should be repatriated.

"There are more than 300 Uighurs here in detention for illegally entering Thailand. So for the time being all of them are now caught in this diplomatic tug-of-war," said Al Jazeera's Scott Heidler, reporting from the Thai capital Bangkok.

The group, who use the name Teklimakan, has been in detention for a year. The group plans to appeal against the decision, their lawyer Worasit Piriyawiboon said.

"I don't agree with the court decision and I'm ready to fight," Worasit said on Friday.

Turkish passports

Thai police detained the group, all from the same family, in March 2014 after they illegally entered Thailand overland from Cambodia. Two of the 13 children in the group were born in custody.

The family claimed to be Turkish and, while still in detention, were issued with passports by the Turkish embassy and granted permission to travel to Turkey.

China insists the 17 detainees are Chinese Uighurs who should be returned to the northwest Chinese region of Xinjiang, according to court documents seen by the Reuters news agency.

Hundreds of people have been killed in unrest in Xinjiang in the past two years, prompting a crackdown by Chinese authorities, and small numbers of Uighurs have tried to flee.

Hundreds, possibly thousands, have travelled clandestinely through Southeast Asia to Turkey.

The Uighurs are a Turkic-speaking people officially regarded as "brothers" in Turkey, which already hosts large Uighur populations.

Source: Al Jazeera and agencies