Prime Minister Prayut Chan-o-cha on Monday rejected rumours he and his wife had wired tens of billions of baht to Singapore.
"If I had that amount of money, why would I have to stand here?" said Gen Prayut at Government House, adding he had been made aware that those who spread the rumours on social media were from Thammasat University.
The university has come under the spotlight after students there rallied for the release of 14 students detained over anti-junta protests.
Gen Prayut said an investigation was underway to track down who spread the rumours about him. He appealed to the public to use "rational thought" to make judgements on any rumours about the government.
He also asked for forgiveness for any negative things he might have said in the past and called on the public to have confidence in him.
"Standing here bears high risk. If not me, who would?" Gen Prayut said.
He also said the regime was working in line with its roadmap for democracy.
"Every country understands and is satisfied with the changes [in Thailand]. The hindrance is that I am not a politician, but I insist everything will go ahead in line with the roadmap. Conflicts should be put on hold for now," he said.