A star prosecution witness yesterday told the Criminal Court that the Election Commission had acted without justification in prolonging the investigation into alleged electoral fraud punishable by party dissolution.

"Even though the investigation had concluded on the involvement of the Thai Rak Thai Party in contracting small parties to contest the April 2 election, the EC still insisted on questioning witnesses instead of filing charges promptly," said Nam Yimyaem, the lead investigator in the electoral fraud case.

Nam was summoned by the court to shed light on the malfeasance litigation against the EC.

The plaintiff, Democrat Party secretary-general Suthep Thuagsuban, has contended that the EC deliberately delayed legal proceedings against the ruling party without justification.

The three defendants are EC chairman Vasana Puemlarp and his two commissioners, Prinya Nakchudtree and Virachai Naewboonnien.

Recounting how the investigation unfolded, Nam said he agreed to lead the probe only after Vasana had promised him a free hand to do the job.

The complaint against the ruling party was filed on March 20 and his initial investigation uncovered sufficient evidence to suspect foul play on April 7, he said.

Following a full inquiry, the investigative panel found that an EC official was involved in the falsification of party membership records that paved the way for candidates from small parties to qualify to contest the polls, he said.

The panel established that two Thai Rak Thai executives, Thamarak Isarangura and Pongsak Ruktapongpisal, were involved in the bankrolling of small parties, Nam said.

It also recommended the prosecution of Thaksin Shinawatra,

the caretaker prime minister, for culpability since the fraud took place under his party leadership, he said.

After reviewing his panel's report, the EC decided on April 21 to initiate judicial proceedings for the dissolution of two small parties, Pattana Chat Thai and Thai Ground, Nam said.

With regard to the ruling party, it wanted the investigative panel to call additional witnesses for questioning, he said.

The panel concluded on May 4 that its report already had sufficient evidence for prosecution, he said, adding that his panel did not have the authority to summon some of the witnesses suggested by the EC.

Nam said he viewed the EC's request for additional witnesses as an undue delay in acting on the probe panel's report.