Powerful cousin of Assad arrested in Syria - reports
Syrian opposition websites have since Monday shared news that Makhlouf has been placed under house arrest.
Makhlouf, who is not only family but also considered part of Assad's inner circle, is the head of a major business empire in Syria.
He is the main owner of SyriaTel, Syria's largest mobile phone company, and has a significant stake in the country's tourism, aviation, oil, banking, and broadcasting sectors.
Analysts generally agree that his huge wealth is down to his close family ties to Bashar al-Assad.
He is seen by Syrian opponents of Assad as symbol of corruption and has been placed under EU sanctions since 2011, when the regime bloodily suppressed anti-Assad protests, for "bankrolling the government and allowing violence against [anti-Assad] demonstrators".
The Syrian news website Eldorar alleged on Monday that Makhlouf, his two brothers Ihab and Iyad, and his father Mohammed were placed under house arrest.
The opposition website All 4 Syria have also said that Makhlouf's shares in SyriaTel had been transferred to the state-owned Syrian Telecommunications Establishment.
The website said that Russia had asked the regime for $2 billion and that Assad asked Makhlouf to pay some of that money.
Makhlouf had been unable to provide the money and this is what had caused the dispute between the two cousins.
Russia has been instrumental in ensuring the Assad regime's survival, intervening militarily in Syria in 2015 against anti-Assad rebels.
All 4 Syria added that documents from Makhlouf's companies were currently being scrutinised by the regime.
On Facebook, Firas Tlass, the exiled son of former Syrian Defence Minister Mustafa Tlass, called reports of a dispute between Makhlouf and Bashar al-Assad "exaggerated".
But he also said that all the directors of Makhlouf's companies had been summoned to the presidential palace regarding their inability to pay the requested sum of money.
Rami Makhlouf's father Mohammed is the brother of Bashar al-Assad's late mother, Anissa. The family have been powerful in Syria since the 1980s and are seen as playing the role of treasurers for the regime.
"I'm getting news from a very reliable source in #Syria that Rami Makhlouf and Bashar Assad have had a major fall out," he tweeted.
"Can't talk about the details until I get the green light, but Assad regime has taken a several actions against Rami over the last two weeks. Watch this space."
Twitter profile Ehsani2 also reported on Tuesday about the alleged rift.
"Reports are that Rami Makhlouf’s offices at the free zone were raided by the money laundering commission . The scope of the investigations has sent shockwaves into Latakia too."