Prosecutors are tracing overseas bank accounts of CJ Group with help from the banks to secure evidence to allegations that the local food and entertainment conglomerate amassed a massive slush fund offshore, sources close to the investigation said Friday.

The country's 14th largest conglomerate has been under a probe on allegations that the company managed a slush fund worth about hundreds of billions of won in total in foreign countries, including the British Virgin Islands, a well-known tax haven, and Hong Kong, and brought the illicit money into the country.

Prosecutors suspect CJ established tens of paper companies overseas to make these illicit money transactions look normal and to dodge a huge amount of taxes.

On Thursday, prosecutors imposed an overseas travel ban on the family owners of the group, including CJ Group Chairman Lee Jay-hyun, vice chairwoman Lee Mie-kyung and representative of CJ affiliates Lee Jay-hwan. The list also included six executives allegedly involved in a series of illegal business activities.

Investigators have obtained credible evidence, including testimony from a former executive who handled the company's finances at one point, Lee hid as much as 350 billion won ($310 million) in over 300 different bank accounts in Hong Kong, a prosecution official said.

Prosecutors are also expanding their probe into allegations that Chairman Lee evaded millions of dollars of taxes and expediently donated part of the secret fund to his offspring.

In 2008, the police revealed that the chairman had amassed large funds under borrowed names, resulting in him paying 170 billion won in taxes. However, the National Tax Service did not file criminal complaints against the company at the time.

The prosecution is currently looking into how much funds the chairman created under name-borrowed accounts and whether he paid 170 billion won in taxes in 2008 from the secret fund the group created overseas. (Yonhap News)