Crime Suppression Division investigators will question six people about whether they provided shelter and assistance for convicted, and now jailed, murderer Somchai "Kamnan Poh" Khunploem while he was a fugitive.
CSD commander Supisal Pakdinaruenart said summons would be issued for the director, the registrar and security chief of Samitivej Hospital, where Kamnan Poh had received medical treatment. They would be called in to testify to police investigators.
A second set of summons would be issued for Vinai Ponpaipal, 50, the kamnan of tambon Samet of Chon Buri's Muang district, Somchai's personal doctor, who is a woman, and the driver of the Lexus SUV in which Kamnan Poh was travelling when he was arrested on Jan 30.
All three were accompanying Somchai in the vehicle.
The names of those listed on the domicile registration of house No 3 in tambon Saensuk of Chon Buri's Muang district would also being checked to see if they were involved. Kamnan Poh is the owner of the house, Pol Maj-Gen Supisal added.
Korbkiat Kasiwat, deputy chief of the Corrections Department, said Kamnan Poh was still being treated at Chon Buri Hospital.
Doctors at the hospital would advise whether or not the convict could be returned to Chon Buri prison.
Asked why Kamnan Poh, as a man convicted of a serious crime, was not put in leg shackles as is common practice, Mr Korbkiat said under Corrections Department regulations, an inmate who is sick or is 60 years old or more must not be shackled unless the prisoner was likely to attempt escape.
Amnat Pratyaphan, the Chon Buri prison chief, said he would listen to advice from doctors at Chon Buri Hospital on whether and when Somchai could be moved back to the prison.
Prison officials had been assigned to keep the convict under watch at the hospital, he said.
Kamnan Poh would likely be put in Zone 2, for the sick or elderly, once he was returned to prison, he said.