Australia's top universities could be aiding the Chinese Communist Party's mission to develop mass surveillance and military technologies, amid rising concerns from Australian intelligence agencies that they are putting national security at risk.

A joint Four Corners-Background Briefing investigation has uncovered extensive collaborations between Australian universities and Chinese entities involved in Beijing's increasingly global surveillance system.

Mangrove communities in the Gulf of Carpentaria are experiencing severe dieback- a condition where wildlife begins to die backwards from the tips of its leaves and roots.

The dieback is said to have resulted from a temporary drop in sea levels, climate change and a sharp increase in sea temperatures.

Traditional owner of the land, Patsy Evans, states that conditions had worsened for wildlife and the land near her home on the Limmen River in the Northern Territory- with the mangrove locations now mainly consisting of dead trees.

Hundreds of migrants from Africa, the Caribbean and Central America found themselves gathered in a migrant detention facility in southern Mexico on Sunday after a futile attempt to head north as part of a caravan aiming to reach the United States.

The group set out before sunrise Saturday from the town of Tapachula, where many had been marooned for months unsuccessfully trying to get transit visas. They carried heavy backpacks, babies and parcels on their heads.

Tasmania was mentioned in a US court case, where a US pharmaceutical giant was noted to have facilitated Oklahoma's opioid crisis, with Judge Thad Balkman stating that Tasmanian alkaloids were a key part of company Johnson & Johnson's pain management franchise.

As the world's largest producer of legal alkaloids, Tasmania supplies 50 per cent of the raw materials that make the world's opioid painkillers.