A man from Kampen has been sentenced to 30 days in jail, 16 suspended, and put on probation for two years for insulting king Willem-Alexander.

The 44-year-old, who spent 14 days in custody after his arrest and so will not go back to prison, was found guilty of deliberately insulting the king by describing him on Facebook as a murderer, rapist and thief.

He also manipulated a photograph of an IS execution and replaced the heads of the victims with that of Willem-Alexander, judges were told.

The police found the social media posts while carrying out an investigation into people who could form a risk to the royal family prior to their King’s Day visit to Zwolle on April 27. The writer, said to be of Turkish origin, was arrested for ‘lèse-majesté’, which means the crime of ‘offending the dignity of the monarch’.

The court ruled the man’s actions were at odds with the constitutional position of the king and the national interest. ‘This behaviour is uncceptable in our society and justifies a criminal sentence,’ the judges said in their ruling.

In April, justice minister Ard van der Steur said the Netherlands is to abolish the law making it a criminal offence to insult a foreign heads of state but that he does not plan to remove the ban on insulting the Dutch monarch.

The Netherlands is one of the few country’s in Europe to have such a crime, for which the maximum sentence is five years in jail.