Leila Rohani is the fourth Iranian wanted for the blast. She is suspected of arranging to rent the Sukhumvit Soi 71 home where the three other Iranian suspects stayed and where the first explosive device exploded, apparently by accident.
The Criminal Court on Thursday issued arrest warrants for the group.
Wiboon said Rohani is now in Tehran, Iran’s capital. “We could not ask Iran to extradite her to Thailand as we have no extradition treaty with the country,” he said.
However, he said Rohani’s absence would not affect the case, as she had only rented the house. Thai police have enough evidence such as footage from security cameras and bomb material found in the house, he added.