Sri Lanka reversed approval for a controversial $1.4 billion Chinese port-related project after the main Marxist party raised objections Friday, a day after giving it the all clear.

Prime Minister Ranil Wickremesinghe said the government would thoroughly review the project involving the reclamation of 233 hectares (583 acres) of land next to a Chinese-owned mega port in Colombo.

He told parliament Friday that two committees of experts would carry out a probe. The project had been approved by the previous regime of Mahinda Rajapakse who had been accused of corruption.

"I got down all the files relating to this project," the premier said. "When I inspected them, I found that all the required reports are not there. There is a deficiency in the environment impact assessment."

His remarks came after the opposition JVP, or People's Liberation Front, strongly objected to the cabinet approving the project, which is Sri Lanka's single largest foreign investment.

Following concerns by the JVP, which provided crucial support for the victory of President Maithripala Sirisena at January 8 elections while remaining an opposition party, prompted the government to reconsider its stand, official sources told AFP.

The JVP noted that the current government itself had raised objections on environmental grounds.

"We will inquire and then ... take a decision," the prime minister said without setting a deadline for the investigation.

Government spokesman Rajitha Senaratne had announced Thursday that the project was not harmful to the environment and therefore it would go ahead.

The uncertainty over the project came as Beijing sent a special envoy, Liu Jianchao, for talks with Sri Lankan leaders, including President Sirisena on Friday, officials said. Details of the talks were not disclosed.

Sri Lankan Foreign Minister Mangala Samaraweera is due to visit Beijing later this month while Sirisena is to make a state visit to China in March.

Launched under the previous government during Chinese President Xi Jinping's visit to Colombo in September, the project gives Beijing a firmer foothold in the Indian Ocean region, a development that neighbouring India is uncomfortable with.

Beijing has been accused of seeking to develop facilities around the Indian Ocean in a "string of pearls" strategy to counter the rise of its Asian rival India and secure its own economic interests.

Sri Lanka is a midway point on one of the world's busiest international shipping lanes that Beijing wants to secure as a maritime silk road for the 21st century.