�Five people have been arrested in connection with the death of a man crushed in a cement mixer at an Upminster farm 10 years ago.

Dad-of-one Lee Balkwell’s body was found wedged between the drum and chassis of the cement mixer at Baldwin’s Farm, Dennises Lane, in the early hours of July 18 2002.

The original investigation by detectives in Essex concluded that the 33-year-old’s death had been a tragic industrial accident and closed the case after just 19 days.

But an inquest in 2008 returned a verdict of unlawful killing through gross negligence.

On Wednesday, a 43-year-old man, from Upminster, was arrested on suspicion of gross negligence, manslaughter, perverting the course of justice and perjury.

A 66-year-old man and two women, 63, and, 49, all from Upminster, and a man, 38, from Southend, were also arrested on suspicion of perverting the course of justice and perjury.

Lee’s dad Les Balkwell told the Recorder: “I’m jubilant that something seems to be happening but also cautious. I have gone through 10 years of twists and turns and I will remain guarded until we actually know what is going on.”

Mr Balkwell, 65, has doggedly campaigned for a full inquiry into his son’s death over the years. This led to an inquiry into the handling of the case by the Independent Police Complaints Commission in 2008.

Its final report this year vindicated some of Mr Balkwell’s suspicions that the original investigation was so substandard as to be “seriously flawed”.

“In our view, it was seriously flawed from the outset,” the report said. “It was mired in assumption that what had happened to Lee Balkwell was a tragic industrial accident.

Investigation failures

“Officers failed to secure potential evidence, failed to interview potential witnesses and failed to treat the death with an open mind.

“The failure of the investigation at that early stage has left evidential gaps which may never be filled.”

The ombudsman earlier recommended that an outside police force be brought in to reinvestigate Lee’s death. But it was later agreed that the West Midlands force would review the original investigation.

It issued 91 recommendations to its Essex counterpart. This led to a new criminal inquiry, headed by Det Chief Supt Lee Catling, from the Kent and Essex serious crime directorate, in August 2010.

The five men and women have been released on police bail until mid-January.