South Korea's professional volleyball league will create new rules that will enable the maximum punishment of expulsion to be applied to players who have a record of school bullying.

The move comes amid a series of bullying allegations lodged against the league's star players, including twin sisters Lee Jae-yeong and Lee Da-yeong, who play for the Heungkuk Life Pink Spiders. 

On Tuesday, Shin Moo-cheol, the secretary general of the Korean Volleyball Federation(KOVO), took responsibility for the allegations, before apologizing to the victims and the nation's volleyball fans.

The federation pledged to introduce new regulations to permanently punish players who bullied their schoolmates. 

Rookie players will be required to submit a written oath on bullying signed by the head of their school before they are drafted, and if the oath is later found to contain false information, they could face severe punishment, including permanent expulsion.

Players already in the league, however, will not be subject to the new regulations.

The twin sisters, meanwhile, have been indefinitely banned from the national team by the Korea Volleyball Association(KVA), the national governing body, while their club suspended them indefinitely.