Police have arrested Rachadech "Nam Oun" Wongtabutr on three charges relating to the death of product presenter Thitima Noraphanpiphat, better known as Lunlabelle.

The 25-year-old was taken into custody at a petrol station in Thon Buri district about 1am on Wednesday when he stopped to refuel his vehicle, in which his parents were also travelling.

Mr Radachech was the last person seen with Lunlabelle, in security camera footage, before her body was found on a sofa in the lobby of a condominium building where he lives, in the early hours of Sept 17.  

He had earlier refused to open the door to police when they went to his room at the condo on Ratchadaphisek-Tha Phra Road to show him a warrant for his arrest. 

He was taken to Metropolitan Police Division 8 and then to Bukkhalo police station for interrogation that continued well into Wednesday morning. He was then charged with detaining Lunlabelle in a way that caused her death, molestation and committing an indecency.

According to police, an autopsy found that Thitima died of extreme alcoholic intoxication, with a blood alcohol concentration of 418 milligrammes per 100 millilitres - a level that causes unconsciousness and death.