Visut has close connections with the ruling Thai Rak Thai Party and will serve as an inspector and independent director.

Visut came under the media spotlight during the long legal debate over whether the selection and appointment of Khunying Jaruvan Maintaka as auditor-general was legal, when Senate Speaker Suchon Chaleekrua sought Royal endorsement for his appointment last year.

After waiting 104 days to be endorsed, Visut withdrew. His nomination was criticised as inappropriate because he is a brother of former Thai Rak Thai MP Sornchai Montriwat.

State Audit Commission chairman Norachai Sripimol later reinstated Jaruwan as auditor-general.

Normally the Finance Ministry appoints permanent secretaries to Krung Thai's board. Visut's last position was deputy permanent secretary at the finance ministry.

Caretaker Senator Chirmsak Pinthong said he would try to determine the reason behind Visut's appointment. He pointed out the case of Prasit Damrongchai, a former national counter corruption commissioner who broke political etiquette to become a defence witness in the asset concealment charge against the prime minister.

Prasit was subsequently appoin-ted a board member of Krung Thai Bank and later joined the board of Thai Airways International.

Sangsit Piriyarangsan, director of Rajabhat Chandrakasem University's Good Governance Research Centre, called for an investigation into Visut's appointment to the bank's board.