The intrigue surrounding American novelist Harper Lee has deepened two years after her death, as the unsealing of her will revealed that her assets have been placed into a secret trust run by her long-term lawyer.

Lee, who died aged 89 in February 2016, lived quietly at the home she shared with her sister in Monroeville, Alabama.

She was not, contrary to popular opinion, reclusive – but she disliked press intrusion and enjoyed pottering around her hometown, eating $6 catfish lunches at her local restaurant.

Her seminal book To Kill a Mockingbird, published in 1960, still sells more than a million copies a year worldwide, generating some $3 million (£2 million) in royalties for the copyright holder, according to court documents.

In addition, Go Set a Watchman, her second novel, published amid controversy half a century after her first, was the best-selling book of 2015 in the United States, and sold more than 1.6 million hardcover copies.