Representatives from Indonesia and Vietnam sat down with their Malaysian counterparts late on Monday to request access to their citizens who have been detained by Malaysian police for their alleged involvement in the murder of a man believed to be the halfbrother of North Korean ruler Kim Jong-un.

The demands come off the back of unsuccessful efforts to gain access from Malaysian authorities, who are insisting on withholding information until the investigation concludes.

Indonesian Siti Aisyah and Vietnamese Doan Thi Huon were detained last week based on CCTV footage of the incident. Consular officers from the Indonesian mission in Malaysia have been unable to reach Siti since her arrest on Thursday.

Indonesian Foreign Minister Retno LP Marsudi initiated a trilateral meeting with her counterparts Panh Binh Minh of Vietnam and Malaysia’s Anifah Aman on the sidelines of the ASEAN Foreign Ministers’ Meeting (AMM) in the Philippine island resort of Boracay.

Retno urged Aman to abide by the 1963 Vienna Convention on Consular Relations and grant Indonesia swift consular access to Siti, who has since been moved to a high-security facility in Cyberjaya to avoid further media exposure.

According to a statement from the Foreign Ministry, Aman stressed that the investigation would continue, because investigators had not finished gleaning information from the two suspects.

Malaysian law allows authorities to refuse access to detainees until the investigation is concluded.

“Even though embassy staff and an appointed legal counsel have met with investigators to confirm that [the detainee] is in good health, consular access is still immediately required,” Retno said in a statement obtained by the The Jakarta Post on Tuesday.

Minh conveyed a similar request for consular access, insisting it was the right of every person in a foreign country.

Aman responded by saying he would coordinate with the Malaysian police, so that access could be granted as soon as possible, but stressed that the investigation had to go on.

Kim Chol, who Malaysia claims was Kim Jong-nam using an alias, was murdered on Feb. 13 by two female assailants at Kuala Lumpur International Airport.

The two female assailants are believed to be Siti and Doan.

Another two men have been detained, and Malaysian authorities are in pursuit of four North Korean nationals also believed to be involved.

A government source, who wished to remain anonymous due to the sensitivity of the situation, suggested that Malaysian authorities would seek an extension of Siti’s detention period as they required more time to substantiate the criminal charges against her.

Retno was in the Philippines for the AMM retreat, kicking off Manila’s chairmanship of the bloc under the theme “Partnering for Change, Engaging the World.”

The Philippine government has proposed six priority areas for this year: a people-oriented, people-centered ASEAN; regional peace and stability; maritime security and cooperation; inclusive growth; economic resiliency; and a model for regionalism.

Retno stressed the need for ASEAN to provide concrete benefits to people in its member states.

“Only by providing concrete benefits can ASEAN remain relevant for communities,” she said.

She also focused on an agreement reached by ASEAN leaders at the 2016 ASEAN Summit to improve maritime security in the region.

Meanwhile, Malaysia’s investigation of the murder case has raised just as many questions in Malaysia as it has in Indonesia, with officials scrambling to reject any possible Indonesian connection.

On Tuesday, Jakarta Police chief spokesman Sr. Comr. Argo Yuwono denied a foreign media report suggesting police were investigating allegations that a North Korean restaurant in North Jakarta serves as an espionage base.

On Monday, the Law and Human Rights Ministry’s Immigration Directorate General revealed the identities of the four wanted North Koreans who fled to Jakarta on the day of the murder.

The directorate general’s spokesman Agung Sampurno said the four were identified as Ri Jaenam, Ri Ji-hyon, Hong Song-hak and O Jong-gil.

He said three of them had continued their journey to Dubai on Feb. 13, while O Jong-gil had gone to Bangkok on Feb. 19.

It is believed they left Jakarta for Pyongyang via Dubai and Vladivostok.

Malaysian authorities said on Tuesday they had still to establish what was used to kill the estranged half-brother of North Korean leader Kim Jong-un, and the body had not been formally identified as no next of kin have come forward.

Kim Jong-nam was killed at Kuala Lumpur International Airport on Feb. 13 with what police believe was a fast-acting poison. Malaysia’s deputy prime minister has previously named the victim as Kim Jong-nam, though authorities have been unable to conduct DNA tests.

“The cause of death and identity are still pending,” Noor Hisham Abdullah, director general of health at Malaysia’s health ministry, told reporters.

(Read also: Malaysia holds reconstruction of Kim Jong-nam murder)

The health ministry official said no DNA samples had been received from the next of kin.

South Korean and United States officials have said they believe North Korean agents assassinated Kim Jong-nam, who had been living in the Chinese territory of Macau under Beijing’s protection.

Malaysia has urged Kim Jongnam’s next-of-kin to claim the body and help with the inquiry, which has sparked a diplomatic row with North Korea, whose officials want the body handed over directly.

Malaysia recalled its envoy from Pyongyang after North Korea’s ambassador in Kuala Lumpur cast doubt on the impartiality of Malaysia’s investigation and said the victim was not Kim Jong-nam.

North Korean ambassador Kang Chol said on Monday that his country “cannot trust” Malaysia’s handling of the probe into the killing.

Responding on Tuesday, Malaysian Prime Minister Najib Razak denounced the ambassador’s comments and reiterated that the investigation would be fair.

“The statement by the ambassador was totally uncalled for. It was diplomatically rude. But Malaysia will stand firm,” Najib told reporters.

Authorities have still to release an autopsy report.

But, the health ministry official said a post mortem examination carried out two days after the death found no evidence of a heart attack or of any puncture wounds on the body.

Malaysian police have arrested a North Korean suspect, and say that four other North Koreans fled the country later on the day of the attack.

Two women from Vietnam and Indonesia have also been arrested on suspicion of carrying out the assault on Kim Jong-nam. There is speculation that they administered a poison by wiping it or spraying it on his face.

Airport camera footage released on Monday by Japanese broadcaster Fuji TV shows the moment the women appeared to assault Kim Jong-nam, who is later seen asking airport officials for medical help.