BEIJING -- A low-ranking Chinese energy official accused of hiding more than $30 million in cash at home in one of the country's most sensational corruption cases admitted his guilt during a court appearance Tuesday in northern China.

The Baoding City Intermediate People's Court said in a statement that Wei Pengyuan, a former deputy chief of the coal bureau under the National Energy Administration, admitted to taking 211 million yuan ($32.5 million) in bribes and failed to account for another 131 million yuan ($20.2 million) in assets.

Under President Xi Jinping's administration, China's Communist Party has launched a sweeping anti-corruption campaign that has netted both senior and junior cadres. Wei's case highlighted the ability of even middling officials to leverage their position to accumulate enormous wealth.

The value of Wei's ill-gotten gains dwarfed that of his indirect superior Liu Tienan, the former head of the National Energy Administration, a powerful economic planner who ranked far higher than the coal official. Liu was convicted last December of accepting $6 million in bribes and received a life sentence.

Wei's case created a sensation in late 2014 after reports said investigators wore out four of the 16 cash-counting machines they used to tabulate his trove, China's largest-ever cash seizure. All told, Wei kept his wealth in four currencies, several kilograms of gold, three automobiles and in calligraphy and art, the court said Tuesday.

Wei's prosecution comes amid heightened scrutiny of China's influential coal industry and its regulators. A documentary that blamed China's air pollution crisis on lax coal industry oversight was widely viewed online earlier this year and stoked public outrage before it was removed by government censors.

Earlier this year the government revised its estimates of coal use sharply upward, underscoring the challenges China faces in shifting away from the cheap energy source even while Beijing has promised to cap Chinese carbon emissions by 2030.

As a national official overseeing the coal industry, Wei had authority over greenlighting coal projects, drafting policy, and approving scientific reviews and safety regulations.

Wei apologized Tuesday during his court appearance, saying he had let down the Communist Party and his child.

"Getting money did not bring me peace and satisfaction, rather it led me to ever-deeper crimes," he said, according to the court statement.

The court has not issued a verdict.