A children's book which describes sexual intercourse as being like a 'jigsaw puzzle' where both parties get a 'tingly, excited, very loving feeling' has divided parents, with some saying it is too graphic.

Available on the shelves of Kmart for just $12, The Amazing True Story of How Babies Are Made, by Fiona Katauskas, is a picture story book that makes 'sex-ed honest'.

But not all have approved of parents being able to get out of having a conversation about 'the birds and bees' with their children, with some calling it 'inappropriate' and others defending it as simply being 'fact'.

The Amazing True Story of How Babies Are Made (pictured), a children's book that details sexual education, has divided parents

The book starts with 'Sex and making a baby', where it pictures a naked man and woman lying together, smiling and looking lustfully into each others eyes.

Giving a detailed explanation of the process that leads to an egg and sperm coming together, the book outlines foreplay without sugarcoating it for five-year-olds.

Moving on to detail the throws of passion, Ms Katauskas' book includes a diagram of the man's penis inside the woman's vagina.

The detailed explanation divided parents on Facebook, with some criticising it as too explicit and others defending it as a necessary tool to educate children.

'What is wrong with the world,' one parent wrote.

'Omg really? There is time for all this c**p, just let kids be kids they don't need to know the finer details,' said another.

'Get a life people, you don't have to buy the book and there is no chance of your kids picking it up in the shop to look at if they are properly supervised,' a defended parent wrote.

The book by Fiona Katauskas describes sex as being like a 'jigsaw puzzle' that gives both parties a 'tingly, excited, very loving feeling'

'The man moves faster and faster until...': The detailed explanation of the book left some parents shocked that it was aimed at children aged as young as five

'Parents buy books like this for kids as a way of teaching them, if you don't want to buy it, don't buy it,' another said.

'Seriously this is inappropriate to be in a kids section,' one comment said.

On her website Ms Katauskas says the idea behind the book came from her struggles to answer a question from her eldest son: 'Where do babies come from?'

'It turned out many of my friends had experienced the same frustration with finding a good sex ed book so I decided to have a go at writing one myself,' Ms Katauskas said.

A recent Facebook debate about the book had parents divided, with some praising its honesty and others slamming it for being too graphic

'Firstly, I wanted it to be straightforward and honest.

'Secondly, I wanted it to include alternative but increasingly common methods of conception such as IVF, sperm and egg donation as well as different types of families and parents.'

Daily Mail Australia has contacted Kmart for comment about the book.