"Two million baht (around USD 56,000) will be given to whomever provides information leading to the capture of the perpetrators and five million baht (USD 140,449) to officials who successfully investigate the case and carry out the arrests," Thaksin's oldest son, Oak Panthongtae said on social media.
"To restore morale and courage among Thais, as well as confidence of foreigners, we must catch the perpetrator as soon as possible. We must show Thailand is not a country where such a perpetrator can get away with it," he wrote.
Thai police is looking for 10 suspects in Monday's explosion, including the individual who placed the bomb near the Erawan shrine in central Bangkok that killed 20 people.
The police are investigating the incident, but despite strict security measures at airports and borders no suspects have yet been apprehended.
Yesterday, Thai authorities tripled the award for information leading to the arrest of the lone bomber to 3 million baht (USD 85,000), Bangkok Post reported.
Thaksin, who governed the country from 2001 until being ousted in a coup in 2006, is in self-exile in Dubai after a corruption conviction that he calls political.
Thaksin is the is among the richest men in Thailand.
