Police in Germany are appealing to the public for tips about the origins of two 17th-century paintings that mysteriously ended up in the garbage at a highway rest stop last month.

According to authorities in the western city of Cologne, a 64-year-old man stumbled upon the two oil paintings in a dumpster at a rest stop near Ohrenbach on May 18. The man, who was taking a driving break at the stop at around 4 p.m., took the paintings with him and later turned them in to police in Cologne.

After the paintings were examined by an expert, police concluded that they are both 17th-century originals, and have put out a public appeal to find their owner: “Who knows the paintings shown and / or how they got into the dumpster at the service area?”

Painting by the artist Samuel van Hoogstraten. Courtesy Cologne Police.

The first painting is a raucous self-portrait by the Italian painter Pietro Bellotti, dated to 1665. The other is a portrait of a boy by the Dutch Old Master Samuel van Hoogstraten, which has not been dated.

The auction record for a Belloti is $190,000, achieved at the Swiss house Koller Auktionen in 2010, according to Artnet’s Price Database. There are multiple versions of the painting, and a very similar portrait, titled Self-Portrait of the Artist as Laughter, was put up for sale at Christie’s London in 2006 (estimate: $55,000–$91,000) and then at Bonhams London in 2008 (estimate: $29,000–$44,000), though both works failed to find buyers. Other versions of the Bellotti painting are in the collection of the Uffizi Galleries in Florence, the Pinacoteca di Brera, and a third was once part of the Scheufelen Collection in Stuttgart.

Meanwhile, works by Van Hoogstraten, who studied under Rembrandt in Amsterdam, have sold for as much as $788,000 (at Christie’s Monaco in 1993). The artist is best known for his experiments with perspective.

A spokeswoman for Cologne’s police department told Artnet News that they are following up on some new leads but have yet to find the owner of the paintings.