The creator of an inflatable sculpture that killed two people after it broke free of its moorings has been arrested on suspicion of manslaughter.

Maurice Agis was questioned yesterday about the deaths of two women who fell from his Dreamspace installation when it soared 70ft (21m) into the air at a park in Co. Durham.

The arrest of the 74-year-old artist followed a lengthy investigation, conducted jointly by police and the Health and Safety Executive, into the cause of the tragedy.

Dozens of families, many with young children, were exploring the giant, walk-in artwork, half the size of a football pitch, when it suddenly soared skywards on a warm Sunday afternoon in July.

Before it flipped over and crumpled to the grounds of Riverside Park, Chester-le-Street, a number of those who were inside the plastic structure fell out. Others were left trapped inside.

Elizabeth Collings, a 68-year-old grandmother, and Claire Furmedge, a 38-year-old radiographer, were killed. Another 13 people were injured.

Among them was a three-year-old girl, Rosie Wright, who fell an estimated 50ft from the sculpture, suffering multiple fractures and a punctured lung.

Her life was saved by a passing anaesthetist, Dr Peter Evans, who stabilised her before she was taken to hospital in a helicopter.

Mr Agis, from East London, was arrested yesterday when he attended a pre-arranged appointment at Charing Cross police station.

He had supervised the installation of Dreamspace in Riverside Park and was present when the incident happened.

Mr Agis, who was questioned by police in the immediate aftermath of the deaths, has described the despair and disbelief he felt when his artwork left the ground.

He grabbed one of the mooring ropes which had broken loose and tried to hold on to it, but was knocked to the ground.

“It happened completely out of the blue. It went straight up, up 20 metres, and then across the ground,” he said. “I was in the midst of it, completely mesmerised. I could hardly move. I was just completely shaken and stunned.” The abstract artist, who said he felt “desperately sad” for the families of those who died, first created Dreamspace in 1996.

In the past ten years the maze-like structure, built of 115 inter-connecting pods, had toured cities across Europe and had been visited by more than 250,000 people.

At the time of the Chester-le-Street incident it was on a tour of Britain, which was partly funded by a £60,000 Arts Council grant, and was next due to be installed at Victoria Park in Hackney, East London.

During the early stages of the police investigation, there was speculation that vandals may have deliberately loosened some of the ropes which tethered Dreamspace to the ground.

Scientists suggested, however, that it was possible that sunny weather on the day of the incident may have heated the structure to a point where it effectively turned into a giant hot-air balloon. Police visited Scotland as part of their inquiries after it emerged that in 1988 another of Mr Agis’s inflatable installations, called Clause 28, had slipped its mooring in high winds during the Glasgow Garden Festival.

Then, the artist and a colleague were lifted 30ft into the air as they held on to mooring ropes. Mr Agis received back injuries and his co-worker fell into the River Clyde.

Mr Agis was released on bail last night, pending further inquiries.

Vital statistics

250,000 Visitors at 25 venues across Europe

50m by 50m Size of ‘bouncy castle’

5m Height

115 Number of interconnected cells, made from thin PVC sheets, inflated to create “a psychedelic cathedral”