KUALA LUMPUR - Johor Prince Tunku Idris Sultan Ibrahim has reposted an Instagram image which triggered speculation about the state's possible secession from the federation, a move experts dismissed as highly unlikely.

Malaysian media reported that the plain image with running lines in Malay was believed to be an extract from an agreement signed nearly 70 years ago before Johor joined the Federation of Malaya.

It was first uploaded by the prince on the photo-sharing platform on Sunday, a day after a federal minister, Datuk Seri Nazri Abdul Aziz, upbraided Johor Crown Prince Tunku Ismail for meddling in politics. The Instagram posting was seen as Prince Tunku Idris backing his older brother.

But following media reports on it on Tuesday, the image disappeared before popping up again on Wednesday, the Malaysiakini news site reported. The posting had garnered more than 4,400 likes by evening.

Malaysiakini provided a translation of what was posted on Instagram. Among other things, the extract said the Johor government agreed to join the federation in 1946 subject to several conditions, including having Islam as the official religion of the state.

"If any of the conditions are violated, Johor will be out of Malaysia," according to the extract.

Though the prince did not include a caption, commentators quoted in the media said it appeared to broach the subject of secession.

But at least one expert has dismissed outright the possibility.

Universiti Malaysia Perlis' Raja Malaysia Institutional Research Centre director Ramlah Adam said Johor's agreement with the Federation of Malaya became null and void after Malaysia gained independence from Britain in 1957.

"These issues are over. The powers of the Malay royalty are now included in the Federal Constitution," she told Astro Awani's news site.