A Dublin man has been given a six-year prison sentence after being convicted of damaging a Claude Monet painting estimated to be worth €10 million at the National Gallery of Ireland.

Andrew Shannon, 49, of Willians Way, Ongar had pleaded not guilty at Dublin Central Criminal Court to damaging the Monet painting entitled ‘Argenteuil Basin with a Single Sail Boat’ (1874) at the National Gallery of Ireland on Clare Street on 29 June 2012.

A jury of seven women and five men returned a verdict of guilty on that charge this afternoon following almost one and a half hours of deliberation on day eight of the trial.

The court heard Shannon has 48 previous convictions in this and other jurisdictions, some of which are for burglary and theft offences involving antiques.

In November 2011 he was sentenced in Wicklow Circuit Court for handling stolen property involving maps dating from 1651 with a value of €6,000.

The Monet painting is now back on display in the National Gallery following a period of restoration.

Judge Martin Nolan imposed a sentence of six years and suspended the final 15 months on strict conditions including that Shannon not enter into a public painting gallery or any other institution or building where paintings are publicly displayed.

The maximum sentence for the offence is ten years.

Director of the National Gallery of Ireland Sean Rainbird said in statement this evening:

"We are satisfied that justice has taken its course. The National Gallery of Ireland conforms to international standards in the care of the collection but recognises that placing valuable and fragile objects on public display carries an inevitable element of risk.

“The Board and Director praise An Garda Síochana and the NGI staff in dealing promptly with the matter at the time of the incident and also thereafter.”

Judge Nolan had earlier directed the jury to find Shannon not guilty of damaging two paintings at the Shelbourne hotel on 8 January 2014.

Sergeant Conor O'Braonain told Kerida Naidoo BL, prosecuting, that Shannon had entered the gallery just before 11am and had gone to where the painting was on display.

He left and returned a short time later and appeared to fall forward striking the painting.

The point of impact was above eye level and to the left hand side of the painting.

Shannon said he had been dizzy and had fallen forward. He had spoken to a number of people, including two tourists from New Zealand and security staff, at the scene telling them he had a heart condition.

He was treated by a paramedic who reported his vitals were normal and he was given GTN spray and aspirin.

During interview he told gardaí he had a heart condition and that was why he had fallen down.

Judge Nolan said he would not expect Shannon to know the value of the painting but he must have known the painting was valuable and historic. He said it was a "peculiar crime" and it was "abnormal" to cause damage in the way he did.

He said he was taking into account Shannon's age and medical condition in sentencing. He said all time Shannon had spent in custody should be taken into account.

A previous jury in the case had been discharged in December 2013 after failing to reach a verdict.