The retired King of the Belgians is facing a €5,000 fine for every day he refuses to take a court-ordered DNA paternity test to finally prove that he is the father of an aristocratic artist.

King Albert II has always refused to recognise Delphine Boël as his daughter, leading to a court case which has lasted more than five years. The legal action could only be brought after the 84-year-old monarch abdicated in 2013.

In November, a court ordered the King to take a DNA test within three months or be seen legally as Ms Boël’s father. An earlier test proved that Jacques Boël, scion of one of Belgium's richest industrial dynasties, was not the 50-year-old multi-media artist’s biological father.

When the deadline was about to expire, Albert’s lawyers referred the case to the Belgium's highest court of appeal, which rules on points of law. On February 14, Valentine’s Day, lawyers for both sides will face off in the court of cassation in Brussels.

Ms Boël’s lawyers will argue that the court should not hear the former monarch’s appeal and point out the king’s advanced age meant that time was of the essence. They will also ask for a daily fine of about £4,300 for every day that Albert fails to submit to the procedure, which is quick and painless.