The committee will examine whether the witnesses can implicate others who may be behind the alleged corruption, according to the source.

Pojaman is wife of deposed prime minister Thaksin Shina-watra.

Uthai Sonlaksub, the chairman of the Rubber Council of Thailand, yesterday said he was tipped off that the people who were behind the corruption in the rubber plantation project are trying to cover up and destroy evidence.

He also heads the sub-committee probing the corruption allegation involving the rubber plantation project.

"We fear that we can only net the small fish because the director-general and ministers who were involved in this project were very careful about not leaving any evidence to link them,'' he said.

Meanwhile the AEC asked its secretary, Kaewsan Atibodhi, to review his proposal to rent a building as an office for the committee, which currently works at the premises of Auditor-General Office, reasoning that the rent is unnecessary and costly.

The AEC also disagreed with Kaewsan's proposal to hire temporary workers to help in the investigation.

The Council for National Security will deploy some legal officials to help the AEC oversee its investigation, the source said.