The remains of a mummified monk from the 17th century, famous for being one of the world's best-preserved cadavers, had a surprise for scientists who performed a CT scan on it: a small foetus hidden under his feet.

The remains of Bishop Peder Winstrup, who died at 74, are some of the best preserved from the 1600s.

However, following a scan at Lund University, of which Winstrup was a founding father, Per Karsten, director of the Historical Museum, found a four-month-old foetus "well hidden under Winstrup's feet".

It remains unclear who the foetus belonged to or who put it in the coffin.

Karsten said: "You can only speculate as to whether it was one of Winstrup's children, or whether someone else took the opportunity while preparing the coffin. But we hope to be able to clarify any kinship through a DNA test."

The scan also revealed that the majority of Winstrup's internal organs remain in place. Internal organs would usually have been removed at burial, but in the bishop's case, "the body was not embalmed in a traditional manner but simply dried out naturally. The good condition of the body seems to be the result of several factors in combination: constant air flow, the plant material in the coffin, a long period of illness resulting in the body becoming lean, death and burial during the winter months of December to January and the general climate and temperature conditions in the cathedral," Lund University says.

The results show that Winstrup had been bedridden for a while before his death, with calcifications in his lungs pointing to the suffering of tuberculosis and pneumonia.

"The gall bladder also has several gallstones, which could indicate a high consumption of fatty food," added Caroline Ahlström Arcini, an osteologist working on the project.

"His right shoulder was slightly higher than his left, due to an injury to a tendon in the shoulder. This would have limited Winstrup's mobility, making it difficult for him to carry out simple everyday tasks such as putting on a shirt or combing his hair with the comb in his right hand."