The Appeal Court on Sunday turned down a request for TV actor Thanapat "Toy Toy" Chanakulpisan to be released on bail, confirming the Min Buri Court's decision on Saturday.
Mr Thanapat, 21, has allegedly confessed to killing his girlfriend Chatsaran Suwannakit, 25, at a two-storey townhouse in Bangkok's Khlong Sam Wa district on Friday.
According to police, the actor confessed that he and Chatsaran quarrelled over his work and she told him to pack up and leave the house. He said she went to the kitchen and came back with a knife. They fought over the possession of the knife and he stabbed her in a blind rage, killing her on the spot.
After the incident, he waited and surrendered when police arrived at the scene.
When Mr Thanapat was taken to the Min Buri Court on Saturday, his lawyet filed for his release on bail while the police asked the court to reject the bail request.
The court denied the bail request on the grounds that the crime carries severe penalties and the suspect could take flight if released.
The lawyer lodged the request with the Appeal Court.
The Appeal Court dismissed the request, saying the lower court's decision was correct.
Mr Thanapat is being detained at the Min Buri Remand Prison. The first 12-day detention period is from Aug 7-18.