The prosecution has determined that some 28-hundred paintings attributed to famed artists Yi Jung-seop and Park Soo-keun are fake.

Officials are considering whether to prosecute figures involved in dealing the works whose authenticity were already in dispute.

Prosecutors said that colored paints developed in the 1960s after the deaths of both artists were used in the forgeries.

Some are confirmed as having been drawn in 1956 by a woman who is 66 years old this year.

The probe is expanding to potential accomplices, Yi's son Tae-seong and an adviser at an old book society known only as Kim who had owned the fake paintings.