Austrian authorities have published a list of 17 instruments and four violin bows that they want to recover in connection with a criminal investigation of violin dealer Dietmar Machold's business activities.

Machold was arrested in Switzerland in March on charges of serious fraud, misappropriation and fraudulent bankruptcy. He stands accused of, among other things, keeping for himself instruments that belonged to his clients, and hiding assets from his creditors.

The list of missing instruments, including several Stradivari and Guarneri 'del Gesù' violins, has been passed to Interpol, the international criminal police agency. According to a report in Austrian newspaper Der Standard, investigators have also made official appeals to authorities in the US, Switzerland, Luxembourg, Germany, the Netherlands and Japan, for their help in the search.

Der Standard claims that the value of the missing instruments, together with the few that investigators have managed to recover, amounts to some €155m. As the criminal investigation continues, creditors including some of Austria's biggest banks are pursuing claims for around €80m in civil insolvency proceedings against Machold.

The violin dealer, meanwhile, remains in Swiss custody. He denies the charges and, according to Der Standard, looks set to resist attempts to extradite him to Austria.