A scientist at the university of Bonn displays a flask in Bonn, Germany. The university says researchers have discovered a carcinogenic substance in the flask believed to have belonged to Queen Hatshepsut, who ruled Egypt 3,500 years ago. -AP Photo

BERLIN: An Egyptian queen who died 3,500 years ago might have poisoned herself accidentally by using a carcinogenic balm to treat a skin complaint, German university researchers said Friday.

This follows research on the dried up contents of a small flask belonging to queen Hatshepsut, who ruled Upper Egypt in the 15th century BC, and which is now in the possession of the egyptology museum of Bonn university, in western Germany.

“It has long been known that Hatshepsut's family suffered from skin complaints” and analysis of the contents of the flask revealed a mixture of palm and nutmeg oil, along with other polyunsaturated fats known to bring relief to people suffering from skin complaints such as psoriasis, the university said in a statement.

The mixture however also include tar residue, a substance now banned in cosmetics because it can cause cancer.

“If the pharaoh-queen was a chronic skin sufferer who often used the balm for short-term relief then, over the years, she might have exposed herself to a high risk” of developing cancer,” scientists from the university's pharmacology department said.

“We've known for a long time that Hatshepsut had cancer and perhaps died because of it. Now perhaps we know what caused it,” said Egyptian collection curator Michael Hoeveler-Mueller.

Hatshepsut, the greatest woman monarch of the ancient world, is buried in the Valley of Kings, across the Nile from Luxor in southern Egypt.

Her rule is seen as a time of stability and prosperity for Egypt, associated more with commerce than conquest, especially the opening of trade routes to Nubia and Somalia in the south. Her most famous landmark is her temple at Deir el-Bahari.