A heart-warming tale of same-sex love and parenting among New York penguins has topped the list of books most complained about in American libraries for the second year running.

Among other literary works in the top ten are The Adventures of Huckleberry Finn (alleged racism) and Philip Pullman’s The Golden Compass (anti-religious).

And Tango Makes Three, by Justin Richardson and Peter Parnell, was published in 2005.

It is based on the true story of Roy and Silo, who formed a couple in New York’s Central Park Zoo.

They attempted to hatch a rock, which was replaced by a rejected egg from a mixed gender couple by zookeepers.

They then adopted the baby penguin Tango as their own.

The book is accused of promoting homosexuality and being ‘anti-family’ as well as unsuitable for its age group.

It has attracted great controversy in US states with parents in Illinois and Missouri requesting the book be placed in a restricted or non-fiction section of the library.

“The complaints are that young children will believe that homosexuality is a lifestyle that is acceptable.

“The people complaining, of course, don’t agree with that,” said Judith Krug, director of the American Library Association’s Office for Intellectual Freedom.

The number of reported library complaints dropped from 546 in 2006 to 420 in 2007.