King Harald V of Norway's sick leave has been extended once again following his recent hospitalisation. The monarch who has ruled the Scandinavian country for nearly 30 years was due to return to his royal duties on Monday, but his leave has now been extended indefinitely.

Just hours before King Harald's expected appearance on the afternoon of Sunday, the first since his return from the hospital, the Norwegian royal court issued a press release to announce that he will not be returning to his royal duties anytime soon.

Meanwhile, his son Crown Prince Haakon will continue to serve as the Regent of Norway for the foreseeable future. His inauguration of the 156th session of the Storting, the Norwegian parliament on Friday, was the first time in 30 years that the traditional opening was carried out by a Crown Prince and not the King of the nation.

"His Majesty the King is still under medical investigation and sick leave has been extended. The Crown Prince Regent will lead the Council of State on Monday 5 October," the statement by the Royal Court on Sunday read.

The 83-year-old monarch, who suffers from an unknown illness, was admitted to a hospital in Oslo as announced on Sept. 25. The court stated that he was having breathing difficulties while noting that COVID-19 illness has been ruled out.

According to a report in Royal Central, the doctors have not been able to identify the reason behind his illness and therefore need to investigate and carry out new tests that may take some time.

A further update on his condition is expected later this week. The King was also supposed to receive the Commander of the Norwegian Navy in an audience at the Royal Palace on Monday morning, a task which was taken over by Crown Prince Regent Haakon.

Norway's King Harald, Queen Sonja, Crown Prince Haakon and PM Stoltenberg attend ceremony to sign a protocol of condolence in Grand Hall of Oslo University
Norway's King Harald (L-R), Queen Sonja, Crown Prince Haakon and Prime Minister Jens Stoltenberg attend a ceremony to sign a protocol of condolence for the victims of last Friday's attacks in Oslo and on Utoeya island, in the Grand Hall of Oslo University July 25, 2011. Reuters

The outlet reports that the King along with his wife Queen Sonja is expected to be in attendance when the Church of Norway marks the start of a new church meeting and a new church council with a religious service in Nidaros Cathedral on Sunday.