A teenager is lucky to be alive after falling into a manhole and being swept through New York's sewers for half a mile.

The 14-year-old was playing with friends when they discovered the open drain in Saratoga County, New York on 8 April. They came across it while on The Zim Smith Trail; though it had been closed for construction work, the boys had entered illicitly.

After stopping to inspect the manhole, one of them fell into to the effluent and was carried away screaming. He travelled for 20 minutes on a tide of urine and faeces before grabbing hold of a stair rail which led up to another manhole.

"He's a lucky young man," said Sgt James Leonard, one of the Sheriff's deputies who pulled the boy out.

Officials said the boy could very likely have been killed in the stretch of sewer that took him across a creek and under route 67 – before he managed to grab hold of the rail.

Upstate New York's Times Union website reported that the boy escaped with minor cuts and bruises and was taken to hospital by his parents.

The Sheriff's office said the construction firm is now under investigation because the manhole should have been covered, despite the surrounding environs being closed to the public.

In 2012, a three-year-old boy had to be dragged from a sewer in Colombia after falling in to a manhole near his home while playing. He was trapped in the drains system overnight.