(CNN) Malaysian immigration authorities have barred recently ousted Prime Minister Najib Razak and his wife, Rosmah Mansor, from leaving the country, they said Saturday.
There had been widespread speculation Najib would fly overseas after his shock election defeat this week, amid calls for him to be prosecuted over the sprawling 1MDB corruption scandal.
"I've been informed that the immigration department is barring me and my family from leaving the country," Najib said in a tweet Saturday. "We will respect the order."
Rumors spread Friday night that Najib would leave the country after he posted on Facebook he planned to take a "short break to spend time with my family whom I have not seen enough of in recent year."
Speaking to Malaysian media, sources close to Najib had dismissed claims he was fleeing, saying he just wanted to go on a break after a grueling election campaign. That did not stop some critics of the former premier gathering at Subang Airport, near the capital Kuala Lumpur, to try and prevent him leaving the country, according to reports.
Asked Thursday if he would pursue a corruption investigation into Najib, Mahathir Mohamad -- who defeated Najib in Wednesday's vote -- said the former leader would be subject to the rule of law. The corruption scandal revolves around a state fund, known as the 1Malaysia Development Berhad, commonly known as 1MDB.
Razak stepped down as leader of his party UMNO and the former ruling coalition Barisan Nasional in a news conference Saturday.
Barisan Nasional had been in power for more than 60 years before losing to a coalition led by Mohamad, his former mentor.
Mahathir was sworn in on Thursday night by the king, Malaysia's constitutional ruler, following a momentous vote in which scandal-plagued Najib was soundly beaten at the polls by his former mentor.
Mahathir's victory upended six decades of control by the Barisan Nasional coalition, which he himself formerly headed as Malaysia's Prime Minister from 1981 until 2003.
He said Friday the king had agreed to pardon jailed politician Anwar Ibrahim, whose case has dominated Malaysian politics for years.
Anwar, once a leading light in the party that ruled Malaysia for decades, was jailed on sodomy charges in 2015, after a trial he says was politically motivated.
Mahathir had promised, if elected, to free Anwar and eventually hand power over to him. Anwar's wife, Wan Azizah Wan Ismail, endorsed Mahathir and served as his deputy in the coalition to oust Najib. She was one of the dozens of opposition candidates elected Wednesday.
Anwar was expected to be released in June, after serving the bulk of the sentence.