A squad of 23 military police and 16 civilians died when the bridge broke beneath them, plunging them into icy water.

Experts say the bridge was badly constructed

According to the Chinese news agency, experts investigating the collapse discovered "irregularities" in both the contracting and construction of the steel bridge.

Another report - in the Communist Party's People's Daily newspaper -said parts of the bridge were rusty, concrete used in its construction was too weak and there were serious welding problems.

The detained private contractor, who has not been named, completed the bridge just three years ago for a state-owned corporation in Chongqing.

The search for more bodies is still going on, with part of the Yangtze River tributary being drained to try and reach victims trapped by the debris.

The collapse has sparked fears surrounding shoddy construction and corruption in the government's massive infrastructure spending spree. The government has said it will crack down hard on officials responsible for quality problems.