Shanghai census results will be announced in April and one demographic expert estimates the city's population might reach 23 million, far over the earlier estimates of 20 million, Oriental Morning Post reported on Tuesday.

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Ding Jinhong, a demographic expert with East China Normal University reckoned that Shanghai has nearly 23 million people registered in last year's census and among them, 14 million are registered population and 9 million are floating population.

And according to the statistics, the population in Shanghai has an annual increase of nearly 600,000 and the city's permanent population is predicted to reach 21 million from 18 million in 2006, said the professor.

Although the exact figure has not been revealed, the head of Shanghai Municipal Bureau of Statistics Wang Zhixiong claimed that according to the census results, the population growth rate of Shanghai was much higher than that of Beijing.