The two American men who tried to courier human body parts out of Thailand were briefly questioned for filing false information about cargo - an offence that carries a maximum sentence of five months, too low for police to make an immediate arrest.
Maj-General Chawalit Prasobsil, a metropolitan police commander, made this point after officers involved in the case were accused of dereliction of duty for letting the men go.
Chawalit said under the Penal Code, police can only make immediate arrests for crimes carrying a minimum three-year jail term.
He was responding yesterday to a statement by the Lawyers' Council of Thailand, which accused Bang Phongphang police of dereliction of duty after they briefly detained then let go Ryan McPherson and Daniel Tanner when they tried to mail five body parts to a Las Vegas address via DHL.
It is believed the men are now in Cambodia.
Chawalit said the officers would have needed arrest warrants to detain them further, while there was also the matter related to the Penal Code's arrest guidelines.