Signals carrying answers to the National Judicial Examination were blocked and replaced with pop songs in Wuhan, the capital of Hubei province, on Saturday, Changjiang Daily reported.

The exam is dubbed the No 1 in China because the difficult test must be passed to become a judge, procurator, lawyer or notary. Only 19 percent of test takers passed last year.

This year, 9,838 people sat the exam in Wuhan.

To prevent cheating, radio-monitoring vehicles were sent to the campus where the exam was held.

The monitoring staff at Huazhong University of Science and Technology discovered signals sending answers at 9:30 am and 10:50 am. The staff replaced the signals with two pop songs, one of which was an English song, It's My Life.

The exam was also video-taped.