Syrian security services have released dozens of employees working in companies of business tycoon Rami Makhlouf, the Syrian Observatory for Human Rights reported.
Up to 185 persons were released in the past 48 hours, while 12 others remained imprisoned, the war-monitor said.
Makhlouf said security forces were arresting his employees to pressure him to give up his companies, most notably Syriatel.
Security agencies had released 41 of Syriatel's employees and 57 former employees of the Al-Bustan charity.
The Observatory also said that 58 army officers and soldiers connected to a former Makhlouf-funded, pro-regime militia had been released.
Also, a former Syriatel employee who requested anonymity told AFP that several colleagues had been freed, including four they knew personally.
The 51-year-old businessman has been embroiled in a power struggle with the state since last year, when authorities seized control of his charity, Al-Bustan, and dissolved armed groups affiliated to him.
Syrian authorities have claimed Syriatel owes money to the government, including outstanding fees for maintaining its operating license.
But in a series of controversial videos posted online, Makhlouf has disputed the claims, alleging that some in power sought to overthrow him and reap a cut of the company's profits and called on Assad to save him.
The government in May ordered the seizure of assets from Makhlouf and his family, then slapped a travel ban on the businessman.
Last year, authorities froze the assets of several businessmen over tax evasion and illicit enrichment, including that of Makhlouf, his wife and companies.