A mother discovered the lifeless body of her lawyer son after he fell from her fifth-storey balcony, an inquest heard.

Fiona Ligonnet found her son William Chapman-Purchas on the ground outside her flat in Oval Road, Camden Town, where he had been staying on the living room sofa.

The 42-year-old plunged to his death overnight, sometime before about 7am on April 25, St Pancras Coroner’s Court heard on Monday.

Ms Ligonnet looked over the balcony after realising he was not in the flat when she woke up – yet the front door was chained from the inside.

“The sliding doors to the balcony were slightly open,” she told the inquest.

“I realised at that point there was no way out of the flat except over the balcony.

“I could not bring myself to look over the edge at first so I want back to my bedroom.

“Then I went back and looked over and there was William on the ground.”

Ms Ligonnet called 999 before rushing down the stairs.

She continued: “I touched him and he was stone cold and I knew he was dead – nobody could have survived that fall.”

The inquest heard that Mr Chapman-Puchas, a solicitor and property developer, was a devoted husband and father to his four-year-old son at their home in Edinburgh.

He had been staying with his mother for about a month due to difficulties with his recovery from surgery undertaken in London on his right arm, which was causing him intense pain following a gardening accident.

Ms Ligonnet added: “He was a very kind, caring person and that’s what makes his death all the harder to comprehend.”

She suggested during the inquest that the high-strength medication he had been given to deal with his extreme pain, oxycodone and amitriptyline, may have caused disorientation, citing reports on the internet of such side-effects.

Senior coroner Mary Hassell returned an “open determination” – the new name for an open verdict – saying she had “no idea” why he left the balcony.

While he was in severe pain, she did not find it “very likely” that he jumped on purpose, saying she could not see any evidence that he wanted to take his life.

She also considered sleepwalking and the effects of the drugs, but said: “All of these are guesses – I simply don’t know how it is that he came to leave that balcony.

“The only honest thing for me to do is to make an open determination, which says ‘I don’t know’.”

The cause of death was given as multiple injuries including a severe head injury.