General Motors vehicles go through assembly after GM celebrated the official launch of the Chevrolet Volt hybrid electric vehicle at GM's Detroit-Hamtramck Assembly November 30, 2010 in Detroit, Michigan.

General Motors (GM) has proposed a $2.8 billion fresh investment in South Korea over the next 10 years as part of its plan to restructure its embattled Korean unit, according to a South Korean senior government official.

The official with direct knowledge of the matter added that the U.S. car maker had requested South Korea to inject funds into GM Korea, in which the country's state bank also holds a stake.

The offer comes as the Detroit carmaker and the South Korean government discuss restructuring options at loss-making GM Korea, one of GM's largest offshore operations.

However, the official added that a close look into GM's proposal was necessary to determine whether the investment plan was sufficient to rescue the unit, which directly employs some

16,000 workers.

"We need to have a closer look through the audit," the official said.

South Korea's trade minister Paik Un-gyu had said on Wednesday that the government has asked for an audit into General Motors "opaque" management in the country in the wake of

the car maker's decision to shut down a factory in a city southwest of Seoul.

"By opaque we mean the high rate of profits to raw material costs, interest payments regarding loans and unfair financial support made to GM's headquarters," Paik told lawmakers in parliament.

Paik added that taxpayers' money would not be wasted in government efforts linked to the GM issue.

GM, which is based in Detroit, has said that its factory in Gunsan will be closed by May, and it is mulling the fate of its three remaining plants in South Korea.

- CNBC contributed to this report.