HONG KONG — The children of the wealthy and well-connected in China enjoy enormous educational advantages, gaining access to elite kindergartens, primary schools and tutors beyond the reach of most Chinese families. But strict meritocracy was thought to reign at one crucial stage: college admission. To gain a spot in a top Chinese university and a ticket to a prosperous life afterward, a student needed a high score on the country’s famously difficult national college entrance examination, not a father with a thick wallet.

Or so most people thought until Thursday, when a confession to bribery by Cai Rongsheng, the former admissions director for Renmin University, called the integrity of the system into question. Mr. Cai, 50, acknowledged to a court in Nanjing, where he is on trial, that he had accepted more than $3.6 million in illegal payments between 2005 to 2013, in exchange for helping 44 students obtain spots at Renmin, a prestigious school in Beijing, or to allow students already there to change their majors, the website of the state-run China News Service reported. Among the wealthy students who benefited was the daughter of a Hong Kong businessman, China News Service reported on Thursday.

No verdict has been announced in Mr. Cai’s case. He was first arrested in late 2013 as he was trying to flee to Canada with a fake passport, according to news reports at the time.

Beyond that, Ji Baocheng, who was president of Renmin University when Mr. Cai worked there, had his Communist Party membership suspended for two years in July, according to China Daily, a state-run newspaper. The paper said that Mr. Ji was suspected of “improper behavior relating to university enrollment” after Mr. Cai was arrested.