HONG KONG — A 44-year-old businessman who became one of China’s wealthiest people as he forged ties with some of the Communist Party’s top leaders before suddenly falling out of favor has died in prison.

The death on Friday of the businessman, Xu Ming, was reported by several news agencies, including the financial newsmagazine Caixin and the Chinese government-owned Wen Wei Po, a newspaper in Hong Kong. China’s principal state-run news outlets, however, have said nothing about Mr. Xu’s death.

Caixin reported that Mr. Xu died of a heart attack in the city of Wuhan, in central China, and on Sunday his ashes were taken to the northeastern port city of Dalian, where his career began. He was to be released next September, according to Wen Wei Po and Caixin.

A multimillionaire before he turned 30, and a billionaire shortly after, Mr. Xu’s most prominent political patron was the mayor of Dalian, Bo Xilai, whose government in the 1990s gave the young businessman lucrative contracts to beautify the city. Mr. Xu’s Shide Group expanded into building materials and real estate and in 1999 bought Dalian’s championship soccer team from the city’s other powerful and politically connected businessman, Wang Jianlin, the chairman of Dalian Wanda Group.