NEW YORK: Two women say their mother’s poem Warm Kitty was ripped off by The Big Bang Theory and now the fur is flying.

The daughters of late writer Edith Newlin filed a lawsuit in federal court in Manhattan, US claiming the lyrics have been used without permission on at least eight episodes of the CBS sitcom and to sell show-related apparel, mugs, magnets, plush toys and other merchandise, reported the New York Daily News.

The New Hampshire women are seeking a cut of profits and unspecified damages from Warner Bros, CBS, Turner Broadcasting and Fox, among other defendants. Their filing claims Newlin wrote her poem around 1933 and later granted one-time permission to Laura Pendleton MacCarteney for use in a 1937 book of nursery school rhymes published by Willis Music.

Warm kitty, soft kitty / Little ball of fur / Sleepy kitty, happy kitty / Purr! Purr! Purr! the original poem reads, according to the complaint.

Daughters Ellen Newlin Chase and Margaret Chase Perry claim Willis Music was out of line when it reached an agreement with Warner Entertainment in 2007 that authorised use of their mother’s poem on The Big Bang Theory with minor changes.