Lawyers representing Saudi journalist Hamza Kashgari have said there are no immigration records of his deportation from Malaysia, insinuating that the 23-year-old had been sent back to his native country surreptitiously and in violation of international laws concerning "non-refoulement".

According to Kashgari's lawyer, Fadiah Nadwa Fikri, neither Sultan Abdul Aziz Shah (Subang) airport nor Kuala Lumpur International airport (KLIA), which both serve Malaysia's capital, had any immigration records of Kashgari's deportation. Without such records, the Malaysian government may have acted in contempt of court, Fadiah said.

Kashgari, a newspaper columnist, was detained at KLIA by Malaysian authorities on 9 February while in transit to New Zealand. He had fled Saudi Arabia two days earlier after messages he posted on Twitter concerning the prophet Muhammad created a furore and caused the Saudi Arabian authorities to issue a warrant for his arrest.

Although Kashgari soon deleted the tweets after posting them, Saudi religious clerics labelled him an apostate and called for his execution. Under Saudi law, apostasy – the renunciation of one's religion – is punishable by death.

Kashgari's case attracted considerable interest from international human rights groups, who voiced fears that he would face the death penalty if charged with blasphemy when returned to Saudi Arabia.

Fadiah and other members of Kashgari's legal team filed a court injunction to stop his deportation from Malaysia, which they received on Sunday. They claim that they were not advised that their client had in fact been deported that day. The Malaysian home minister, Hishammuddin Hussein, had said that authorities did not receive the court order.

Fadiah called Kashgari's treatment was "a case of public interest" and said: "If he was deported after the injunction was given, then it can amount to a contempt of court, and we're looking at filing a case against the [Malaysian] government if that is so," she was quoted as saying in Free Malaysia Today, a local news portal.

Fadiah's comments come one day after Kashgari filed a habeas corpus writ through Lawyers for Liberty, an NGO in which Fadiah is a member. The group declared as respondents the inspector-general of police, the immigration director general, the home minister and the Malaysian government. The high court of Malaysia will hear an objection to the writ next week, Malaysian news agency Bernama reported on Tuesday.

Lawyers for Liberty has claimed that Malaysia breached international law by refusing Kashgari asylum, effectively "condemn[ing] him to torture and near certain death" in Saudi Arabia.

Fadiah told Free Malaysia Today that discrepancies in Malaysia's account of Kashgari's arrest and deportation could prove that the government's actions against him were unlawful.

"On 10 February, the officer representing the police, Ramli Mohamed Yoosuf, told news agency AFP that Kashgari was arrested pursuant to a request by Interpol, but on 13 February, Home Minister Hishammuddin said that there was no request by Interpol for deportation," she said.

Fadiah also disputed claims by Hishammuddin that Kashgari was deported according to the "long-standing arrangement" between Malaysia and Saudi Arabia, as there were no such treaties between the two countries.

"[Kashgari] came here to seek asylum, so according to international laws and human rights conventions, a country has the obligation to provide [and] to protect an individual who is fleeing his own country for fear of prosecution," Fadiah said. "Malaysia is bound by customary international law: this is based on the principle of non-refoulement."

She added that his counsel may file a case with the United Nations human rights body against Malaysia.

Hishammuddin on Monday defended Malaysia's decision to deport the Saudi journalist and said the country should not "be seen as a safe country for terrorists [or] those who are wanted by their countries of origin … [or] as a transit country". He said the deportation followed a request from the Saudi government and that allegations that Kashgari could be tortured and killed if sent back home were "ridiculous" because Saudi Arabia was a respectable country.

Kashgari's deportation provoked debate worldwide, not least in Malaysia, which has long considered itself a "moderately Muslim" nation. Sisters in Islam, a Malaysian advocacy group, on Tuesday condemned Kashgari's deportation and questioned Malaysia's commitment providing a safe haven for asylum seekers.

"Do we not have any autonomy in deciding our own policies, or do we … adhere to the whims of countries we perceive as more powerful?" the group asked in a statement.

"Sadly, despite … attempt[s] to promote Malaysia as a moderate Muslim country, the Malaysian government has failed to match its rhetoric with its actions."