GENEVA (AFP) -- Swiss customs authorities have slapped a billionaire with a $4 million fine for failing to properly declare some 200 artworks imported into Switzerland, according to media reports confirmed by officials Sunday.

Financier Urs Schwarzenbach has for years been bringing precious artworks by the likes of Yves Klein and Giovanno Segantini into Switzerland without declaring them to customs officials, or reporting their worth at far below their actual value, several Swiss media outlets reported.

Suspecting the billionaire of importing artwork illegally, Swiss customs authorities opened an investigation in 2012.

The probe concluded earlier this month that he had effectively dodged duties worth 10 million Swiss francs ($10 million), which he was ordered to repay, along with 4 million franc fine, the NZZ am Sonntag, Sonntagszeitung and Le Matin Dimanche weeklies reported.

Swiss finance ministry spokesman Daniel Saameli confirmed the content of the reports to AFP.

According to the papers, Schwarzenbach has agreed to pay back the 10 million francs, but is contesting the fine.

The 68-year-old's lawyers in London told the papers he denied any intentional wrongdoing, and wanted to present his side of the story to the district court in Zurich to clear his name.

Schwarzenbach, who is based in Britain and is reportedly a good friend of Prince Charles, had brought at least 123 works of art into Switzerland without declaring them, with some ending up on the walls of his luxury Zurich Dolder Grand hotel, the papers said.

Fake receipts

In one case detailed in Sunday’s articles, he purchased a Giovanno Segantini painting, “Le due madri,” for 1.4 million Swiss francs at a Christie's auction in Geneva in 2011, and quickly flew it to Britain, thus avoiding Swiss taxation.

But the painting reportedly reemerged in his luxurious Villa Meridiana in St. Moritz in the Swiss Alps, without him ever paying duties on it.

Other artworks reportedly brought in under the radar include a painting by Russian geometric abstract artist Kazimir Malevich, valued at 16 million francs, and Yves Klein’s “MG41 (L’Age d’Or),” the papers said.

When he did declare artwork, Schwarzenbach, whose fortune was valued last year by Swiss financial magazine Bilanz at 1.25 billion Swiss francs, sometimes reportedly presented fake receipts for amounts far lower than what he had actually paid.

On June 16, 2012 he is alleged to have presented Gottardo Segantini’s “Paysage alpin” to Swiss customs officials along with a receipt for just 10,000 francs.

That is less than a tenth of the 105,000 euros ($108,000) he actually paid for the piece, the papers reported.

In all, the case concerns more than 200 works of art, with a combined value of at least 130 million francs, they said.