An official inquiry has found that a freak storm caused the sinking of a cruise ship on China's Yangtze river with the death of nearly 450 people and recommended the captain be probed for possible crimes, state media said Wednesday.

The Eastern Star capsized with mostly elderly holidaymakers on board in June, the country's worst shipping disaster for more than six decades.

A six-month investigation by the cabinet-like State Council said the sinking was caused by "freak" strong winds and heavy rains, an official website said.

Despite widespread public anger, the report only named relatively low-level government officials as responsible for the disaster which killed 442, and recommended sacking as their heaviest punishment.

The Eastern Star encountered the squall during a trip from Nanjing to Chongqing on the night of June 1. A downburst, instead of a tornado as reported previously, produced strong winds that overturned the vessel, the report said.

It said the captain and other staff made an "inadequate response" to the situation, including failing to send a signal calling for rescue.

Other flaws by the firm included lax monitoring of the vessel's condition, it said.

A year of deadly accidents in China has raised questions over the ruling Communist party's ability to keep citizens safe and its resolve to hold officials to account.

The inquiry recommended that Captain Zhang Shunwen -- who was one of just 14 survivors -- be passed to "legal departments" for investigation.

A further 43 executives and officials were named as having failed in management, according to a summary of the investigation published by state news agency Xinhua.

They include seven people from the company and 36 from government departments -- with the highest ranked at "vice provincial level" and the majority of even lower rank, Xinhua said.

But the highest punishment recommended for officials implicated in the accident is "sacking," the report said.

The report concluded that the disaster was caused by a mixture of bad weather and management errors, according to the website of the State Administration of Work Safety.

- Tight censorship -Officials from the ruling Communist Party in past decades have covered up the details of accidents and disasters.

The growing use of the Internet and social media in recent years spurred more detailed reporting of some disasters.

But media controls have been stepped up under current President Xi Jinping, and access to the Eastern Star sinking site and to relatives of passengers was tightly limited, with censors quickly deleting online criticism.

A report in the Beijing News at the time of the sinking said changes made to the Eastern Star when it was converted into a ferry may have made it more susceptible to capsizing.

Similar controls on online comments and reporting were imposed after an industrial explosion in the northern port city of Tianjin in August killed more than 200.

More than 70 people are still missing people following a landslide in Southern China this month that occurred despite multiple warnings.

Some internet users reacted to the ferry investigation with scepticism.

"The result (of the inquiry) is released, and its useless," Tian Boxue wrote on Chinese Twitter-equivalent Sina Weibo.

Another Weibo user wrote: "The higher level the official, the lighter the punishment. Corrupt officials are clearly protected."