Comedian Frankie Boyle has denied "punctuating" material with racist references or making "gratuitous" use of black people, in his libel trial at the high court.

Boyle also claimed the characters he played might express racist views but he did not.

He is suing Mirror Group Newspapers for libel over an article that described him as "racist comedian Frankie Boyle".

Boyle said he has actively campaigned against racism and parodies racists – and claims the newspaper "misunderstood" the context of his use of language in jokes.

The Daily Mirror publisher is defending its article, published on 19 July 2011.

Boyle on Wednesday answered questions from barrister Ronald Thwaites QC, for MGN, who pointed to a joke about US President Barack Obama and said the comedian was making "gratuitous use of a well-known black man".

He added: "You are punctuating your programme with racist references that some people will find clever and others will find normal and acceptable."

Boyle denied the allegation and said he was playing characters who were "dressed up".

"These are phrases that a racist will use," he told jurors. "There is no way they are an endorsement of racist terminology. It is the absolute opposite of that."

He added: "If I dressed up as Godzilla, people would not accuse me of wanting to crush Tokyo myself."

• To contact the MediaGuardian news desk email editor@mediatheguardian.com or phone 020 3353 3857. For all other inquiries please call the main Guardian switchboard on 020 3353 2000. If you are writing a comment for publication, please mark clearly "for publication".

• To get the latest media news to your desktop or mobile, follow MediaGuardian on Twitter and Facebook.