An ambitious Chinese plan to build a replica of 15th century explorer Zheng He's "treasure ship" has run aground, reports said Monday, with some questioning whether the vessel will ever sail.

According to the state-run China Daily newspaper, work began in 2005 on the replica, which, if completed, would be the world's largest handmade wooden ship.

Yet the 71.1-metre-long vessel now stands half-finished at a shipyard in the eastern Chinese city of Nanjing, with those involved in the project offering conflicting explanations for the delay.

Admiral Zheng He, China's most famous sailor, embarked on a two-year expedition in the 1400s that took his fleet of 300 ships and 30,000 men as far as Africa.

He was a Muslim from Yunnan who became an imperial eunuch after being taken captive and castrated at the age of 10 by the Ming as their armies overthrew the area's Mongol rulers.

At court he rose quickly to become a key adviser, before being entrusted with his voyages of exploration.

Some writers claim he beat Christopher Columbus to America, but that version of history is widely seen as controversial.

The replica is a joint project between the government of Nanjing's Gulou district and a Malaysian electronics company, according to the China Daily.

Nanjing's Modern Express newspaper reported last week that construction on the project has been halted for almost a year due to lack of funds.

But Bian Guanghong, head of the company building the ship, denied that money was behind the delay.

"The craftsmen on the project ... are old and need to have a break this summer. That's the reason for the suspension," he told the China Daily.

One of the shipwrights rebutted the suggestion, telling the newspaper that "some problems between the two companies and the workers should be solved first".