J. League chairman Mitsuru Murai on Monday vowed to take swift action over the racist taunting of Kawasaki Frontale's Brazilian striker Renato in a league match on Saturday.

Yokohama F. Marinos banned a teenage spectator from watching their games indefinitely after he was caught waving a banana at Renato during the first half of Saturday's 2-0 victory over Frontale.

"The standard was (set) in 2010," said Murai, referring to the first incident of racial abuse toward a player by fans in the J. League, for which Urawa Reds were fined ¥5 million.

"I want to take into overall account, the social changes since and the way clubs handle (these situations). I want a quick decision," said Murai.

A penalty will be decided on through a J. League tribunal.

Marinos acted swiftly after TV footage of the supporter spread on Twitter. Team officials identified the fan and questioned him after the match at Mitsuzawa Stadium.

The supporter denied his actions were racist, but the club clearly felt otherwise.