Does MGL have any power of detention of goods and conveyances?

Yes, under Section 69 of MGL, an officer has power to
detain goods along with the conveyance (like a truck or
other types of vehicle) transporting the goods. This can be
done for such goods which are being transported or are
stored in transit in violation of the provisions of MGL. Goods
which are stored or are kept in stock but not accounted for
can also be detained. Such goods and conveyance can be
released after payment of applicable tax or upon furnishing
security of equivalent amount.