She was detained a week ago without an arrest warrant, a source says.
Outraged citizens say the funds should be used to repair badly damaged thoroughfares used by everyone.
The government has sent veterinarians to administer a vaccine to live animals to prevent the virus from spreading.
The governor of Xieng Khouang province took land leased to a restaurant owner and sold it to the country’s central bank.
Those involved in the trade sell the elephant tusks to wealthy China and other Asians.