Andy Lee is facing claims his kids' book has ripped off another children's classic.

Earlier this year, Andy Lee showed off another one of his talents when he published a children’s book.

Titled Do Not Open This Book, it sold 40,000 copies in just two days.

But now the radio host is facing claims he copied another book, The Monster At The End Of This Book,  published in 1971 by classic children’s series Sesame Street.

There are certainly striking similarities between the two books.

Both feature blue cartoon characters and use reverse psychology on the reader to not turn to the next page.

The book in question. Image via Facebook.

But Lee hit back on Friday saying he hadn't even heard of the book written by Jon Stone before now.

"When Hamish first got the book [Andy's] he said, 'It reminds me of that book, The Monster At The End Of This Book', but I've never read that," he said on the Hamish and Andy radio show.

"I can understand why people think there are similarities, and I'm kind of chuffed by that."

Lee insisted it was all his own work after he wrote the book on a flight in under an hour.

Nonetheless, Lee appears unlikely to face a lawsuit. Media lawyer John-Paul Cashen told the Herald Sun copyright laws did not protect ideas, but rather the expression of ideas. He pointed out the two books used very different language, imagery and layout despite running under a similar concept

Speaking on The Project earlier this year, Andy said he only started to write the book to surprise his nephew.

Scroll through some of Andy's best moments. (Images via Instagram.)

"I thought about writing a book for his birthday present, and I thought it would be a nice thing to do," he told Carrie Bickmore.

"And, so about five months before his birthday I had this idea for a book, I wrote it up and gave it to my best mate Horgs, who's a kids' book publisher, and said, 'Can you just make one copy for me?'. He rang me back a few weeks later and said, 'I asked the other publisher and they'd like to print this'.

Andy with sister when he surprised her with the book. Image via Youtube.

Even though he was initially hesitant, Lee eventually said okay but made him swear there would be no promotions so his sister could still be surprised.

To reveal the gift, he actually organised with a bookstore to have it set-up and he would casually walk by with his sister.

And my goodness, it was so cute.

Of course, she shed a couple of tears and Andy held onto little George.