The precious gems reportedly had no paperwork to prove their origins and had been concealed among various decorative items in the apartment.
The jewels are said to be worth over €3 million, and represent one of the biggest seizures of the type in recent times in Portugal.
According to newspaper Jornal de Notícias (JN), the man had been under investigation by the Loulé GNR’s NIC criminal investigation bureau for around three months, as part of a case involving fraud.
Following ongoing surveillance, officers waited for the right moment to take action, which came about on Tuesday, mid-afternoon.
Armed with search warrants, NIC agents raided the suspect’s property and, after going through it with a fine-tooth comb, uncovered the gemstones.
The valuable jewels were confiscated and the man arrested.
The investigation will continue to verify whether there are any possible connections between this case and a precious gemstone smuggling network.
In 2016, the PJ police detained a 69-year-old Portuguese man suspected of being part of a group that operated a network of suppliers and rough gemstone transporters from third countries, without certificates of origin. The stones were later cut and introduced into the international market. At the time, action was staged in the Algarve, Lisbon and the Azores.
To obtain licensing, precious stones must meet a number of criteria for certification. A mechanism regulated by Law 5/2015 of 15 January, aims to prevent the introduction of so-called “blood diamonds” originating from conflict zones.