'Sunday Oliseh has been released from his working duties. The cause are the events after the home game against Hansa Rostock,' the club said, declining to give further details.
Media reports said Oliseh clashed with Iranian striker Vahid Hashemian in the Bochum changing rooms.
Speaking about the incident, Hashemian told German news agency SID: 'Sunday and I discussed the match on the field. He said 'Why do you always have to dribble'? So I said to him that he was not the trainer or his assistant or the captain.
'After the match, Sunday came up to me in the changing room. We spoke for five seconds, then I suddenly had his head in my face. My nose was broken. I was shocked.'
Bochum signed Oliseh, 29, on loan from local rivals Borussia Dortmund in January 2003 and had appeared set to make the move permanent.
However, the midfielder, who has previously played for Juventus, Ajax and FC Cologne, will now return to Dortmund at the end of the season, which is when the loan deal expires.
Oliseh was part of the Nigeria squad that won the African Nations Cup in 1994 and the Olympic title in 1996.
But he fell out of favour with the national team leadership after he led a protest over non-payment of air fare refunds during the African Nations Cup in Mali in February 2002 and was not selected for Nigeria's World Cup squad later that year.