Malaysian authorities have deported a young Saudi journalist accused of insulting the prophet Muhammad on Twitter, a police official said.

The move came despite concerns from rights groups that he may be persecuted at home.

The Jeddah-based newspaper columnist Hamza Kashgari was detained on Thursday upon his arrival in Malaysia. Some Saudis have reportedly made death threats against him or called for him to face criminal charges over remarks he tweeted that many considered offensive.

The national police spokesman Ramli Yoosuf told the Associated Press that the 23-year-old was handed over to Saudi officials and flown back on Sunday morning. Flight arrangements were handled by the Saudi authorities, he said.

The Malaysian home minister, Hishammuddin Hussein, said any charges against Kashgari were a matter for the Saudi Arabian authorities.

Muhammad Afiq Mohamad Nor, a lawyer appointed by Kashgari's family, said the move was unlawful because he had obtained a court order to block the deportation. He said he had not been informed by police and was still verifying if the Saudi had indeed been sent back.

"We are concerned that he would not face a fair trial back home and that he could face the death penalty if he is charged with apostasy," the lawyer told the AP.

Amnesty International has called Kashgari a prisoner of conscience and called for his release.

Human Rights Watch said Saudi clerics had condemned Kashgari as an apostate who must face punishment. The rights group had urged Malaysia to allow him to seek asylum.