A Portuguese official says it's impossible to put a price on the booty of the Bom Jesus, a 16th century Portuguese ship carrying gold, silver and elephant tusks that was discovered in 2008 along the Namibian coastline.

Teresa Ribeiro, Portugal's secretary of state for foreign affairs, says the artifacts found in the remains of the shipwreck have a "unique historical value."

The Portuguese news agency Lusa quotes Ribeiro as saying during a trip to Namibia that the archaeological site is securely maintained in line with international standards. Ribeiro says she has told Namibian authorities that exhibitions from the shipwreck should be held in both Portugal and Namibia.

Lusa says Ribeiro was planning on Monday to visit the Namibian central bank, where a vault contains coins from the Bom Jesus.