SK Shipping confirmed Monday that it is being investigated by the National Tax Service, but dismissed rumors concerning tax evasion.

“The tax authorities’ move appears to be part of the regular tax audit of our company,” company spokesman Hong Chang-hyo told The Korea Herald.

“We are giving necessary documents to the tax authorities and are also holding meetings to respond to their questions,” said Hong.

But speculation about possible wrongdoing still persists as the investigation into the shipping unit under SK Group is being conducted by the NTS‘ fourth division, which specializes in large companies’ tax evasion and business corruption cases.

The tax investigation, which started on Feb. 25, is expected to last until mid-May.

But market experts said the probe may be related to the NTS’ latest attempts to fight offshore tax evasion. The government started in January intensive investigation against 30 individuals and companies, which includes some conglomerates.

In 2014, SK Group turned out to have 69 branches in offshore tax havens, the highest number out of 237 branches set up by 61 conglomerates, according to local business tracker Chaebul.com.

The NTS refused to comment on the probe, saying it could not comment as to whether the investigation into SK Shipping is related to the latest crackdown.

SK Shipping, which is planning to go public this year, posted 1.52 trillion won ($1.26 billion) in sales and 135.5 billion won in operating profits in the third quarter of last year. Its sales dropped by 216 billion won and operating profits increased 82.2 billion won over the same period of the previous year.

By Shin Ji-hye (shinjh@heraldcorp.com)