BEIRUT — A rift at the highest levels of Syria's ruling Assad family erupted into the open Thursday as President Bashar al-Assad's powerful cousin appeared in a Facebook video appealing for help to avert a government attempt to seize his assets.

Whispers that there had been a split between Assad and Rami Makhlouf, a business tycoon who served as the family’s main ­money-spinner, had been circulating for months following unconfirmed reports last summer that he had been placed under house arrest.

In the video message addressed to Assad and posted late Thursday night, a haggard-looking Makh­louf left little doubt that he has indeed fallen out of favor with the president and has lost the ability to speak to him in person. Referring to his cousin as “Mr. President,” he said he had paid all the taxes his companies owe and does not currently have the money the government is seeking.

He also hinted at rifts within the regime, blaming what he described as his “suffering” on an unidentified “cadre” of officials.

This group “always frames me as the suspect, the one in the wrong, the bad guy,” he said.

“We do not trust those people,” he added, appealing to the family solidarity that has sustained the 50-year-old regime by saying he would be willing to give money directly to Assad but not to the state.

“I’m a small and simple part in this whole thing,” he pleads. “Mr. President, I implore you, this is the truth.”

The video appears to confirm the most significant power struggle within the heart of the family since Bashar took over from his late father Hafez in 2000. It also points to severe strains within the Assad regime as the Syrian economy collapses and the ­civil war grinds on, analysts said.

“It’s very big,” said Bassam Barabandi, a former diplomat who defected from the Syrian Embassy in Washington in 2012. “Rami was in the inner circle from day one of Bashar’s rule. He’s built into the regime. To take him out would be like a divorce.”

The unprecedented airing of a family feud follows various attempts to seize assets of the companies Makhlouf controls as part of a wider push by Assad to raise money for Syria’s cash-starved government. Other business executives have been targeted, too, including Assad loyalists.

But as a member of the ruling family, the nephew of Assad’s mother, Anisa, and a childhood companion of Assad, Makhlouf is by far the most influential.

The immediate trigger for his outburst isn’t clear. Last month, Egyptian authorities announced they had seized four tons of drugs hidden in a shipment of milk from Syria to Libya by a Makhlouf-owned company. A month earlier, the government froze his assets for a second time, citing taxes owed by his fuel import company, Abar Petroleum.

There is also a new claim on millions owed for licensing by Syriatel — Syria’s biggest cellphone company, in which Makhlouf has a controlling stake — according to the Syria Report, which monitors the Syrian economy. Makhlouf said he is being pressured to hand over in excess of $100 million.

Syria watchers and diplomats have offered several explanations for the feud. Some date it to pressure put on Assad last year by Russia, his ally, to pay overdue bills for fuel, prompting Assad to demand that his wealthier cousin hand over the cash. Makhlouf refused, said a diplomat who was based in Damascus at the time and spoke on the condition of anonymity to discuss sensitive information.

Others say that intensifying rivalry within the Assad clan over control of the country’s rapidly dwindling resources has ­fueled intrafamily tensions, notably long-standing animosity between Makhlouf and Assad’s wife, Asma, who runs a rival charitable organization.

Makhlouf represents a hard-line wing of the family, which favors using military force to crush government opponents and frowns on women playing a prominent role, as Asma does, said Barabandi.

That would also put him at odds with Russia, which has been trying to persuade Assad to make political compromises to end the war. Numerous unconfirmed reports in local media have said Russia was behind the push to investigate Makhlouf’s companies, perhaps with a view to recovering some of its own expenditures on Syria.

Yet others say Makhlouf’s legendary wealth is at risk of compromising Assad, potentially even turning the cousin into a rival. One of Makhlouf’s sons, Mohammad, boasted last year of his lavish lifestyle in promotions in newspapers around the world, including photographs showing him aboard his private jet.

At a time when more than 80 percent of Syrians live below the poverty line, prices are spiking and ­the currency has collapsed, the Makhloufs’ conspicuous consumption risked reigniting opposition to the government, said ­another diplomat who monitors Syria.

Makhlouf had been an early target of the protesters who took to the streets during the anti-Assad uprising in 2011 and singled out the mighty Syriatel as a symbol of the corruption and nepotism they were denouncing. Makhlouf subsequently announced that he would step aside from business life and focus on charitable works. He nonetheless retained a significant stake in ­Syriatel, continued to operate other businesses and launched a militia called Bustan, after the name of his charitable foundation.

Makhlouf said in the video that he retreated from the public eye to avoid becoming a “burden” on Assad. This was one of several references Makhlouf made to his desire not to burden or embarrass the president, and they seemed to imply that he has the potential to do so. He also offered pointed reminders of the extensive patronage network he operates, employing thousands of Syrians in his companies and distributing aid to the families of those who have died fighting for the family over the past nine years.

Above all, however, the dire state of Syria’s economy appears to have added urgency to the need for Assad to raise cash, said the diplomat, who likewise spoke on the condition of anonymity.

“It is first and foremost a dearth of money. Makhlouf has not paid up enough and is unwilling to do so,” the diplomat said. “This dearth of money is really dire. The money is needed. The coffers are completely empty.”