A 22-year-old Thai student could face two years in prison for hacking into the prime minister's Twitter account and posting messages accusing her of incompetence, officials said today.

Akawit Thongdeeworakul surrendered to the authorities after he was contacted by investigators searching for the anonymous hacker who posted eight tweets on Sunday mocking the premier.

"He told me his act was innocent as he didn't realise it would be a big deal," information, communication and technology (ICT) minister Anudith Nakornthap said at a news conference attended by the suspect.

"He was remorseful for what he did and said he will use his computer expertise to help the ICT ministry fight against lese majeste websites (sites that insult the monarchy). He confessed that he did it alone."

The university student, wearing sunglasses and a baseball cap, remained silent and expressionless during the news conference.

Anudith said the suspect could be charged under a section of the Computer Crime Act that carries up to two years in prison.

"I would like this case to be an example for those who would like to do something like this," he added.

Thailand has drawn criticism from rights groups for suppressing freedom of speech using the Computer Crimes Act and lese majeste legislation, which bans criticism of the king, queen, heir or regent.

Yingluck described the Twitter attack as a "violation of people's personal rights" and suspended her account.

The sister of ousted former leader Thaksin Shinawatra was lambasted on a variety of subjects in the tweets, including her response to recent serious flooding and a number of key government policies.