A US independent bookshop is offering refunds to disappointed customers who bought Harper Lee’s Go Set a Watchman, after they discovered it wasn't the breezy summer read they were expecting.

The work should be seen as an “academic insight” into Lee’s development as an author, rather than as a “nice summer novel” say the proprietors of Brilliant books in Traverse City, Michigan.

Brilliant Books has said that its “dozens” of customers are owed “refunds and apologies” over what they say has been misleading presentation of the recently-published novel.

“It is disappointing and frankly shameful to see our noble industry parade and celebrate this as ‘Harper Lee’s New Novel’,” the bookseller has posted on its website. “This is pure exploitation of both literary fans and a beloved American classic (which we hope has not been irrevocably tainted). We therefore encourage you to view Go Set a Watchman with intellectual curiosity and careful consideration; a rough beginning for a classic, but only that.”

Brilliant Books compares the novel to Stephen Hero, James Joyce’s original draft of A Portrait of the Artist as a Young Man.