A Bulgarian woman might be linked to the murder of a Chechen leader, local official has said.
Investigators have tapped her phone line to discover that she often contacted two suspects. Those men had been arrested as supposed accomplices in the assassination of Zelimkhan Yandarbiyev.
The woman has been interrogated and then released.
She was running a tourism agency, and claimed those phone calls were related to the job.
Yandarbiyev was killed in an explosion last February. The ex-chief of Russia's Federal Security Service then attributed his death to a "blood feud" among rival Chechen groups in the Persian Gulf emirate.
The Chinese military believe that Beijing and Moscow must resist pressure from Washington together