Bulgarian authorities released a computer-generated image Thursday of a suspected accomplice in the killing of five Israeli tourists and a Bulgarian driver in last month's bus bombing, and a photocopy of a fake driver's license he apparently has used in the country.
The image of a man with short dark hair is accompanied by a photocopy of a fake Michigan license, in which he appears to be wearing a wig. Police confirmed the license was fake and that it has been used by the accomplice.
Police also said that he may have used other identities as well, and asked people who might have seen him to report to the nearest police station.
The ministry didn't provide any further details, but the new photo appears to confirm earlier suspicions the bomber wasn't working alone. The country's prime minister has said that a sophisticated group of conspirators was involved in the suicide bombing, but the government has otherwise provided very little information about the ongoing investigation.
The attack in Burgas, a popular vacation destination for Israeli tourists about 400 kilometers (250 miles) east of the capital, Sofia, occurred shortly after the Israelis had boarded a bus outside the airport.
Officials still have not commented on the identity of the suicide attacker or how many people were believed to have been involved, and also declined to back up Israel's claims that Iran and the militant group Hezbollah played roles.
Earlier this month, Bulgaria asked member countries of the international police organization Interpol to publicize a computer-generated image of the suspected bomber. Interpol issued a Black Notice, which is used to seek information about unidentified corpses, to each of its 190 member countries, saying it is disseminating the image in hopes of engaging the public's help in identifying the man.
Authorities have examined his fingerprints, his DNA and another fake Michigan driver's license, issued in the name of Jacque Felipe Martin with an address in Baton Rouge, Louisiana. The license was different from the other Michigan license used by the suspected accomplice.
Borisov said DNA samples from the suicide bomber have been shared with all partner security services, but no match has been found in their databases.
Security camera footage just before the attack showed the suspected bomber wandering in and out of the bus terminal in Burgas, wearing a baseball cap over long hair, a T-shirt and plaid shorts. His bulky backpack was packed with TNT powder.