Denmark’s Crown Prince Frederik has rushed from the Winter Olympics in South Korea to be with his father, Prince Henrik, whose condition has “seriously worsened”, the Danish Royal House said in a statement on Friday.

Prince Henrik, the husband of Queen Margrethe, was last week diagnosed with a tumour officially described as benign”.

Prince Frederik’s Australian wife, Crown Princess Mary, visited Prince Henrik in hospital in Copenhagen on Friday along with two of her children.

Her father-in-law had been hospitalised following an illness that began during a private trip to Egypt.

“I know my brother is not well. It seems to be a question of weeks,” Prince Henrik’s brother, Etienne de Monpezat, told Danish newspaper BT on Friday.

Born Henri Marie Jean Andre de Laborde de Monpezat in France in 1934, Prince Henrik married Queen Margrethe in 1967. They have two sons, the Crown Prince and Prince Joachim.

The Royal House in September said Prince Henrik had been diagnosed with dementia.

That announcement came after Prince Henrik had been the centre of controversy when he announced he did not wish to be buried next to his wife, saying he was unhappy she never acknowledged him as her equal.