The authorities seized 1,263 life jackets that failed to correspond to safety standards in the raid on the workshop in the centre of Izmir, a city on the Aegean Sea, the Dogan news agency said.
Izmir is a major hub for refugees and migrants seeking to make the risky crossing in flimsy boats to EU member Greece.
The news of the seizure comes a day after Turkish authorities announced that the bodies of 36 migrants had been found on its Aegean coast after their boats sank in bad weather while trying to cross to the Greek island of Lesbos.
Yesterday Turkish newspapers published harrowing images of the corpses of the refugees as they were found on Tuesday morning, with their faces in the sand and wearing life jackets that had apparently been of no use.
Dogan said that the so-called life jackets seized were filled with “packaging” rather than the proper material needed to keep the wearers alive for hours in the water.
It said that four people were found working in the workshop, including two young Syrian girls.
The confiscated life jackets have been sent to the local police for examination and an investigation has been launched.
AFP correspondents who reported on the wave of migrants heading from Turkey to Greece this summer had seen a booming trade in life jackets in Turkish resorts for sale at suspiciously low prices.
Turkey, which is home to some 2.2mn refugees from Syria’s civil war, has become a hub for migrants seeking to move to Europe, many of whom pay people smugglers thousands of dollars for the risky crossing.
The International Organisation for Migration (IOM) said Tuesday that 1,004,356 migrants and refugees reached Europe in 2015 but 3,771 died while crossing the Mediterranean.