has said he is looking into reports that a member of his shadow cabinet sang "Hey Jews" to the Beatles song "Hey Jude".
Dan Carden has denied the Buzzfeed news website's story that he changed the lyrics on a private bus to London from the Cheltenham races in March last year.
Mr Corbyn said it was an "awful story" and "totally unacceptable" if true.
Asked about the reports on a visit to Leeds, he said: "Dan Carden has emphatically denied that.
"It is an awful story and if it's true it is utterly and totally unacceptable. I am looking into it."
Mr Carden, who is seeking to be re-elected as MP for Liverpool Walton, tweeted: "I have been categorical in my denial about allegations relating to a coach trip some twenty months ago.
"This was a coach full of journalists and MPs. If anyone genuinely believed any anti-Semitic behaviour had taken place, they would've had a moral responsibility to report it immediately.
"Yet this allegation is only made now when a General Election is imminent.
"I stand by my record as an anti-racist campaigner. I would never be part of any behaviour that undermines my commitment to fighting racism in all its forms."
