The efforts of renowned poet Patrick Kavanagh to promote his book 'The Green Fool' are detailed in an 80-year-old file released by the Department of Justice.

It reveals that a garda investigation was opened in 1938 after the poet called to several Dublin book shops demanding that his book was displayed in the front window.

The manager of Fred Hanna’s on Nassau Street told a Detective Garda Sergeant that he was not afraid of Mr Kavanagh, but feared he might do some damage.

He claimed the Monaghan native had said: "You have 15 minutes to put my book in the window. This is an ultimatum."

The Grafton Book Shop manager told a similar story.

The manager of that store says he told Kavanagh that it would be an impossible state of affairs if every Irish author came round and threatened him into stocking their books.

The investigation began after it was brought to the attention of gardaí by a priest who believed the 'The Green Fool' was somewhat anti-Catholic in tone.

Reverend Fr Senan of Church Street in Dublin also suggested the Department of Justice should consider using the Censorship of Publications Act in this case.

The garda leading the probe concluded his report saying that he had made inquiries as to Kavanagh’s present address, but had not been able to ascertain it.

The book that Patrick Kavanagh promoted with such gusto in 1938 that it sparked a Garda investigation a newly released Dept of Justice file reveals. Read more on ⁦@rtenews⁩ pic.twitter.com/eyqOhqTgcx — Mícheál Lehane (@MichealLehane) December 28, 2018

Reporting by Mícheál Lehane and Conor McMorrow