Officials have admitted answers to a standardized test taken by tens of thousands of sixth-grade students in Guangdong province's Leizhou were leaked, with one official allegedly insulting a reporter investigating the case.

The local public security bureau and discipline inspection department are looking into the answers having been disclosed ahead of the test on June 25. Students were informed of the leak and told their scores were immediately nullified.

Some parents claim the test is the middle school's entrance examination, though the city government had announced the discontinuation of test-based enrollment. However, schools required students to fill out middle school applications before taking the latest exam.

The nine-year compulsory education law says students can attend nearby schools without taking any test. Nevertheless, parents hoping to send their children to better schools further away must pay at least 2,000 yuan for enrollment, unless their children score highly on the exam, Nanfang Daily reported.

Leizhou education bureau director Lin Tao said the bureau has stopped grading papers since learning about the leak. He denied the government was using the test for enrollments and said the exam was instead "organized by every elementary school to gather data about the realities of the teaching and learning situations".

Lin also denied plans to organize another test. But the father of a 12-year-old Leicheng Jiguan Primary School student told the Southern Metropolis Daily he received a text message from the school announcing a June 3 retake.

Lin allegedly responded to a New Express journalist's inquiry about why the students had to fill out applications before the test by saying: "That's a foolish question," the Guangzhou-based newspaper reported on June 27.

Municipal education bureau officials refused to answer any questions from China Daily.

The 12-year-old said it became obvious the test materials had been leaked when several students arrived to take the exam with notes that turned out to be the exact answers. Parents said the cheat sheets were sold for 400 yuan, a large sum in Leizhou.