Deputy national police chief Surachet Hakparn confirmed on Tuesday that an arrest warrant would be sought for an unnamed officer in the next two days.
The Nation understands that the arrest warrant will be for Pol Lt Col Withoon Rangsiwuthaporn, Sararat’s ex-husband.
Withoon was suspended as deputy superintendent at Ratchaburi’s Ban Pong Police Station after his ex-wife was arrested last month.
He was questioned for a second time on Tuesday and gave valuable information but insisted on his innocence, Surachet said.
Withoon told police that Sararat had asked him to pick up the car of one alleged victim, Suthisak Poonkwan, from Udon Thani. Withoon then drove the car to Nakhon Pathom, where Sararat sold it to a pawnshop in the province, the deputy chief said.
He added that Sararat also committed her crimes on weekends, when she travelled with her victims to create an evidence trail.
“We have to check who took weekend breaks with her and what triggered her to commit the crimes, such as repayment deadlines for debts.”
Sararat had run up debts and transferred cash to many people, including criminals, he said.
Evidence found in Sararat’s car included loan agreements, as well as traces of cyanide. Police are now investigating criminal accounts involved in the case, Surachet said.
Withoon said he divorced Sararat due to financial issues but investigators believe he did so to escape prosecution, the deputy police chief said.
The couple reportedly divorced three years ago but had lived together in police accommodation in Kanchanaburi until last year.
Withoon will initially be charged with embezzlement and using a fake licence plate, Surachet said.
Sararat and Withoon are the only suspects in the case.
Police believe Sararat, 36, poisoned 14 victims to steal their valuables and escape debts she owed to them. One alleged victim survived and alerted the police. Officers arrested Sararat at the Chaengwattana government complex in Bangkok on April 25. She has so far been charged with 10 murders, but Surachet said police have enough evidence to prosecute her for all 14 deaths.