The National Security Council (NSC) and the Pheu Thai Party on Saturday dismissed reports that Thaksin Shinawatra was planning to meet a senior figure in the southern insurgency movement.
Thaksin's personal adviser, Noppadon Pattama, said on his Facebook page that the fugitive former prime minister did not meet Hassan Taib, liaison office chief of the Barisan Revolusi Nasional (BRN).
Thaksin was now in China and not Malaysia as several media outlets had been reporting, said Mr Noppadon.
NSC secretary-general Paradorn Pattanatabut said there had been no confirmation of the earlier reports from state agencies working on issues relating to the violence in the South.
On Friday, an unnamed military source said Thaksin would meet Mr Hassan in Terengganu.
The source said the former premier planned to ask Mr Hassan to be more flexible about the BRN's five demands outlined in a video posted on YouTube last Sunday, so that the peace talks between the NSC and BRN could progress.
The source also claimed that an alleged meeting between Thaksin and Mr Hassan in Dubai earlier this year might have been the catalyst for the peace talks, which began in February.
Defence Minister ACM Sukumpol Suwanatat said he didn't know anything about the alleged meeting.
ACM Sukumpol said Thaksin had nothing to do with the matter and that authority for resolving the southern unrest rested solely with the current government.
Thaksin was premier in 2004 when the unrest in the South, which had been dormant for many years, exploded anew. The catalyst was a heavy-handed military crackdown that left 32 suspected insurgents dead at the Krue Se mosque in Pattani.
Pheu Thai deputy spokesman Anusorn Iamsa-ard said on Saturday that Thaksin expressed his concerns about the violence in the deep South during a party meeting held via Skype.
"He told us that Malaysia was willing to help Thailand to put an end to the southern violence," Mr Anusorn said.
Separately, Democrat Party deputy leader Thaworn Senneam said Thaksin's involvement would exacerbate the problem in the South if he were allowed to play a role in the peace talks.
He accused Thaksin, the de factor leader of the ruling Pheu Thai Party, of wielding influence over the government.
Thaksin's role in the negotiations could damage the country, Mr Thaworn said, adding that Prime Minister Yingluck Shinawatra should warn her brother not to meddle.