A Bangkok court on Monday postponed giving its verdict in the closely-watched trial of a Thai web editor accused over remarks about the monarchy posted by other people on her website.

Chiranuch Premchaiporn, who faces up to 20 years in prison, denies allegations that she did not remove 10 online posts perceived as critical of the monarchy quickly enough in 2008.

Judge Nittaya Yamsri said the Bangkok Criminal Court was unable to finish considering the evidence in time due to the large number of documents filed by both sides.

"The court postpones its verdict to 30 May at 10am," she said.

The case against Chiranuch, the editor of the popular Prachatai news website, has shone a spotlight on Thailand's strict lese majeste and computer laws.

Chiranuch, who has become a figurehead for freedom of expression in Thailand, appeared shaken by the court's announcement.

"I don't know what to say. I prepared for a verdict, I did not prepare for this," she told AFP.

The royal family is a highly sensitive topic in politically turbulent Thailand. King Bhumibol Adulyadej, who is revered as a demi-god by many Thais, has been hospitalised since September 2009.

Observers say prosecutions under lese majeste legislation -- which bans criticism of the king, queen, heir or regent -- surged following a 2006 coup by royalist generals that left the kingdom deeply polarised.

The country saw huge street protests in Bangkok and a violent crackdown in 2010.

Chiranuch's case has received widespread international attention, because of both the length of the potential sentence and the fact the accusations relate to other people's comments that she says she removed as quickly as possible.

She has also made the unusual decision to deny the charges -- many accused in Thai lese majeste trials opt to plead guilty in the hope of receiving a royal pardon.

"This is a quick solution for those who have that option but I don't think that's the right way to resolve the issue. That just means that it will remain an open wound in Thai history and the Thai justice system," she told AFP last week.

Recent trials have sparked fierce debates on Thailand's laws, including over a 61-year-old man who was jailed in November for 20 years for sending text messages deemed insulting to the monarchy.