China's Ministry of Transport said Tuesday that no large-scale oil spill had been found in waters where two vessels collided off China's east coast.

A Panama-registered oil tanker, carrying 136,000 tonnes of condensate oil, caught fire Saturday evening after it collided with a Hong Kong-registered bulk freighter.

Zhao Ruxiang, an expert with China's Yantai Oil Spill Response Technical Center, said a simulation test showed condensate oil in the water can evaporate so quickly that it will leave little residue - less than 1 percent after five hours.

Yet it is toxic and volatile when exposed to air, with a possible risk of triggering explosions, Zhao said.

As of Monday, rescuers had found one body that was believed to be one of the 32 missing oil tanker crew members - 30 Iranians and two Bangladeshis.

Search for the missing is ongoing, with 13 rescue vessels searching an area of 900 square nautical miles, while closely monitoring the condition of the burning oil tanker, the ministry said.

The collision occurred around 8 p.m. Saturday in waters about 160 nautical miles east of the Yangtze River estuary.

All 21 crew members on the bulk freighter -- all Chinese nationals -- were rescued, according to the ministry.