Auditor-General Pisit Leelavachiropas said a letter was sent to the Interior and Defence ministries urging them to review the use of state budgets by local administrative organisations.

Intelligence suggested that some Yingluck followers would be invited to Bangkok to show moral support for the former premier on August 25 when the Supreme Court is scheduled to deliver its verdict on the charge of negligence in implementing a rice-pledging scheme that resulted in massive losses for the state.

The government is also seeking multibillion-baht damages from her.

Yingluck’s supporters have gathered at the Supreme Court building during the hearings by its Criminal Division for Political Office Holders in her trial for negligence in managing the rice-pledging scheme.

Hundreds of them gathered on July 21, when the last court hearing was held, and again on August 1, when Yingluck read out her closing statement. There were allegations that free transport was provided for people to travel from the provinces to offer moral support for the ex-PM.

Thousands of supporters are expected to show up when the court delivers its verdict on August 25.

Authorities have warned against mobilising large numbers of people to gather outside the court, pointing out that it could be deemed contempt of court or violating the law on public demonstration or the ban on political gatherings.