Seoul, Mar 22(AFP): South Korean police have accused four men of using illegal spy cameras in motel rooms to film and livestream videos of more than 800 couples in one of the largest-scale examples of the country's spycam epidemic.

Police said on Thursday that the men installed tiny cameras - all of them with a lens just one millimetre wide - in 42 rooms in 30 motels, hidden inside hairdryer holders, wall sockets and digital TV boxes.

They then livestreamed the footage 24 hours a day to a subscription website with about 4,000 members, hosted on an overseas server.

Some viewers also paid a 50,000 won ($44) monthly supplement for access to "exclusive" content - edited highlights available on repeat, according to the AFP news agency.

More than 800 couples were shown on the site over three months, mostly having sex, police said.

"It was the first case we caught where videos were broadcast live online," they said in a statement.

The gang earned about seven million won ($6,203) from the scheme, police said.

Hyper-wired South Korea has been battling the increasingly widespread proliferation of so-called "molka", or spycam videos, which largely involve men secretly filming women in schools and toilets, among other places.

The latest case is unusual for involving couples and the livestreaming element.

More than 5,400 were arrested for spycam-related crimes in South Korea in 2017, but fewer than two percent were jailed.

Earlier this month K-pop singer Jung Joon-young, who rose to fame after coming second in one of South Korea's top talent shows, admitted secretly filming himself having sex and sharing the footage.

Jung appeared at a court hearing on Thursday to determine whether an arrest warrant will be issued on allegations he shared sexually explicit videos without consent. A court decision is expected Thursday night or Friday.

Last year, Seoul witnessed several demonstrations by tens of thousands of women protesting against spycam videos as part of the country's #MeToo movement, demanding stricter punishment by the government.

In South Korea, motels are a relatively affordable option for many travellers from home and overseas, and a popular destination for couples seeking privacy away from parents or other family members.

But they have also long been associated with illicit sex business and crime.