Pai Dao Din a day after the Khon Kaen court denied him bail again (FB/Jom Petchpradab)
In a copy of the letter was acquired by the Bangkok Post (copy below):

The detained defender had been hoping to make bail so he could attend the award presentation ceremony in person, but his request was denied. In refusing Mr Jatupat’s bail requests, the Region 4 court and Khon Kaen Provincial Court described him as a flight risk who could tamper with evidence. The laureate is thus unlikely to be abel to travel on 18 May to the award ceremony in Gwangju and Mr Jatupat’s mother Prim Boonpattararaksa and her husband Viboon will represent their son and receive the award on his behalf.
National Human Rights commissioner Angkhana Neelapaijit, who won the Gwangju Award for Human Rights in 2006, described it as a prestigious accolade.
Source: Envoy queries Korea award for Jatupat | Bangkok Post: news