Tight security was in place around the courthouse, amid government fears that Thaksin loyalists could react to the verdict with violence. The decision was not expected for several hours after the Thai stock market closes for the day.

Nine judges of the Supreme Court are broadly applying mostly untested anti-corruption statutes in determining whether Thaksin - a telecommunications tycoon before entering politics - became “unusually wealthy” by abusing his position at the head of government from 2001-2006.

They could order the confiscation of the $2.9 billion of his family's assets frozen in Thai banks. Thaksin and an unknown portion of his family's wealth are safely ensconced abroad.

Thaksin, ousted in a 2006 coup and facing a jail term in Thailand, was monitoring the proceedings from exile in Dubai, where he was scheduled to provide a running commentary via video link.