If a probe found the councillors had used the money wrongly, they would face legal action, she warned.

Two years ago, when Samak Sundaravej was governor, the Audit Committee sent a letter to the Interior Ministry and the cabinet seeking to stop the Bangkok Metropolitan Administration (BMA) from giving councillors the left-over money.

Last year, the new governor, Apirak, set up a committee to consider the suggestion and a proposal was made to amend the Bangkok Metropolitan Administration Act.

But the BMA recently gave Bt1.14 billion remaining after its budget allocations to the 57 councillors - Bt20 million per person - without setting conditions as to how the money was to be spent, as had occurred previously.

Jaruvan yesterday said the Office of the Auditor-General (OAG) had in the past submitted evaluation reports to the BMA stating the councillors' spending was erratic, sometimes of little use and deprived the city of certain benefits. In the absence of accountability, it was found some had favoured companies owned by people close to them.

As the BMA had ignored its reports, the OAG planned to conduct an in-depth investigation, Jaruvan said.

She said the probe should not be difficult, even though the BMA had not set conditions for spending the money.

Standard audit procedures would be used to judge whether any expenditure was inappropriate or if there was corruption, she said.