An apparent malfunction that delayed a draw at China's major lottery has aroused suspicions from the public after the winner walked away with more than 60 million yuan ($9.2million).

Managers of China's major lottery said on Monday night that there were no wrongdoings.

The China Welfare Lottery Issuing and Management Center disclosed on its website that a majormal function in its data system resulted in the postponement of Sunday night's lottery.

The draw was later held and broadcast on television on Monday morning, with a migrant worker from Guangdong province winning more than 60 million yuan.

The delay and ensuing actions aroused intense suspicion and criticism from members of the public, with many claiming there could be a backroom deal or corruption behind the delay. Some called on the government to launch a thorough investigation.

A man who identified himself as Zhang raised his concern to the Central Commission for Discipline Inspection of the Communist Party of China, the country's top anti-graft body, Beijing News reported.

Zhang told the newspaper that he doesn't think the data malfunction has anything to do with the draw and the center's explanation was unreasonable. He suspected that the postponement was made because the center would not let anyone, rather than the person it selected, win the lottery and it needed time to orchestrate the draw.

"I don't know which department oversees the lottery center so I have to report my concern to the Central Commission for Discipline Inspection. I hope the watchdog can review the fairness of the latest draw," he was quoted as saying by the report.

The Central Commission for Discipline Inspection told the newspaper it has received the report, without saying how it will deal with it.

In response, the lottery center said it is an international practice that all sales data must be collected before the draw can be performed. In addition, China's Lottery Management Regulation stipulates that sales data must be published before the draw.

The welfare lottery saw sales of 205 billion yuan ($33.6 billion) in 2014, up 16.6 percent year-on-year. Last year it raised more than 57 billion yuan in public welfare funds, the lottery center said earlier this month.

Lottery sales cover the jackpot as well as lottery management fees and the public welfare fund, it said. The majority of money allocated to the public welfare fund goes to social insurance programs, poverty relief, initiatives for the disabled as well as donations to other charity projects. From 1987 to 2014, sales of welfare lottery tickets totaled 1.17 trillion yuan, raising 360 billion yuan in public welfare funds, according to the center.