Anwar Sha doesn't know if his refugee sister and her three young daughters are alive or dead.
They risked their lives on a rickety wooden boat on November 29 to escape the squalid camps of Cox's Bazar in Bangladesh after fleeing violence in Myanmar five years ago.
Mr Sha received news a week ago that his sister Zahida Bagum and her daughters, aged between eight and 12, were among about 200 Rohingya Muslim refugees stranded in the Andaman Sea.
They have been drifting in a powerless vessel without food and water in Southeast Asia for weeks.
Up to 20 are estimated to have died from dehydration and starvation, or to have drowned.
Meanwhile, 58 hungry and weak Rohingya Muslim men disembarked from a boat in Indonesia's northern province of Aceh on Christmas Day after weeks at sea.
It is unclear if they were part of the larger group including women and children still adrift.
Indonesia is not a signatory to the United Nations 1951 Refugee Convention but a 2016 presidential regulation provides a legal framework to help refugees on boats in distress near the coastline, and allow them to disembark.
The UN refugee agency has urged states in the region to launch a rescue mission.
"The UNHCR repeats its appeal to all responsible States to rescue those on the boat and allow them to safely disembark in line with legal obligations and humanitarian traditions."
Mr Sha, an Australian citizen who arrived in the country as a political refugee in 2000, said he didn't know if his sister and her children were alive.
"About a week ago we heard they were somewhere between Indonesia and Malaysia," he said.
Distraught that his sister took the perilous journey with her daughters, Mr Sha said he feared for their lives.
"We can't track them, it's a dire situation."
Ms Bagum, in her mid-50s, briefly spoke to her Malaysian-based husband by satellite phone about a week ago but she was unaware of her location.
He recorded her desperate, tearful plea.
"We are dying here, we have no food and no water. What are you doing there? Do something for us," she said.
"The children cannot talk, they are too weak. We have nothing, we have to help each other."
Mr Sha, 42, is a human rights activist and adviser to the Burmese Rohingya Community in Australia.
Rohingya Muslims have been persecuted by Myanmar's military and Buddhist nationalists for decades, triggering their move to other Southeast Asian countries with Muslim majorities.
In 2017, a genocidal crisis forced most to Cox's Bazar, where they live in dire conditions and are vulnerable to exploitation.
Keysar Trad, chief executive of the Australian Federation of Islamic Councils, is disappointed a written appeal sent last week to Prime Minister Anthony Albanese has so far gone unheeded.
The federation urged the government to coordinate with Indonesia to rescue the Rohingya refugees adrift, in pursuit of a safe place to live.
"His office used to respond very quickly before he became prime minister. I'm not holding my breath. The (former) Morrison government was very quick to respond,'' Mr Trad said.
The prime minister did not respond to a request for comment.
Home Affairs Minister Clare O'Neil said the government did not comment on "operational matters".
Mr Trad said help was critical.
"These are desperate people who are fleeing for their lives and livelihoods," he said.
The UN refugee agency said it was "deeply dismayed that repeated calls to rescue and safely disembark people stranded on boats in the Andaman Sea and Strait of Malacca are not being heeded''.
"Several reports indicate dozens of people have already died during this ordeal," the agency said.
