Victims of transnational online scams in East Asia, Southeast Asia, Australia and New Zealand lost up to $114.1 billion last year, a UN report said Tuesday, with estimated losses at least tripling from 2023.

Southeast Asia, especially Cambodia and Myanmar, has emerged as a regional hub for crime syndicates running fake romance and cryptocurrency investment schemes in which scammers -- some willing, others trafficked -- defraud internet users around the world, often from fortified compounds.

But under pressure from several countries including the United States, Britain and China, authorities in the region say they are cracking down on the illicit industry.

Several alleged scam network bosses were extradited from Cambodia to China in the last year, after Washington and London sanctioned firms and individuals accused of operating far-reaching cyberscams fuelled by human trafficking.

Online scams, mostly from investment fraud, across the specified regions cost victims an estimated $88.3 billion to $114.1 billion last year, according to the new report from the UN Office on Drugs and Crime (UNODC).

The combined losses far exceed the $18-37 billion estimated to have been lost in 2023, and reflect "the dramatic scaling of this criminal economy", the report said.

In the last two years China, South Korea and Taiwan reported the largest losses from scams in the region, each losing billions of dollars, it added.

The cyberscam industry has ballooned in Southeast Asia in recent years, with organised criminal groups initially mostly targeting Chinese speakers before widening their reach and targeting victims globally.

The wider criminal ecosystem of Southeast Asia -- which includes the illegal drug trade, online scams, human trafficking, illicit banking and real estate investment -- has also transformed over the last decade, according to the UNODC.

Organised criminals are "moving away from a fragmented system of locally rooted criminal syndicates toward an increasingly integrated, transnational, and technologically sophisticated criminal economy", it said.

The shift has challenged conventional law enforcement and threatened regional governance, and economic and social stability, the UNODC added.

"What we are seeing is a shift in which groups that stayed within their own geographic domain and criminal specialty are now operating across multiple illicit markets at once, relying on the same service streams," UNODC regional representative Delphine Schantz said in a statement.

"Their operating model looks like corporate franchising: imagine specialised departments for laundering money, trafficking people, smuggling migrants, and harvesting data, all plugged into the same, service-based interconnected network."