TOKYO (AFP) - Fallen Japanese pop star Aska has been arrested on drugs charges after calling police to tell them he was being spied on at home by a hidden camera, police and reports said on Tuesday.

The singer - one half of folk rockers Chage And Aska - was slurring on the call when he insisted he was being watched, Jiji Press and other media said.

Police who visited his Tokyo home on Monday arrested the 58-year-old on suspicion of using stimulants and MDMA, a force spokesman told AFP.

Aska was given a three-year prison term, suspended for four years, in December 2014 for possession and use of the same drugs.

Narcotics are heavily regulated in Japan and the police make much of high-profile arrests.

Writing on his blog, Aska denied reports that a police urine test had come up positive for drug use, saying the result was "not positive. It's 100 per cent impossible."

Chage Aand Aska made their musical debut in 1979 and remain hugely popular in Japan and other parts of Asia including Singapore, Hong Kong and Taiwan.