A cannabis gardener was today found guilty of murder in a case where a body has never been found.

No motive for the killing of Murray Thompson from St Albans, who vanished two and a half years ago, has ever been established.

James Evans, 23, of Bushey Mill Lane, Watford, pleaded not guilty to murdering 34-year-old Mr Thompson, but was convicted.

He also denied conspiracy to produce cannabis and two counts of doing acts to pervert the course of justice, but was found guilty of those charges.

The "chief executive" of the skunk cannabis growing operation in Watford, Lee Sullivan, 47, of Hudson Road, Watford, was convicted of perverting the course of justice and three charges of intimidating a witness. He was cleared of one count of intimidation.

The jury heard Mr Thompson, who was a courier for a Hemel Hempstead firm, worked as a "gardener" at a Watford cannabis factory.

He lived with his Zimbabwean girlfriend Rachel McDowell in St Peter's Street, St Albans, where she worked for Santander bank in the city.

Mr Thompson, who was known as Muz or Muzza, was last seen on the afternoon of April 20, 2010. He arrived in his van close to a flat in St Albans Road, Watford. It was above a chemist shop and was one of five being used for the cultivation of skunk cannabis in Watford.

The jury at St Albans Crown Court was told that Evans was at the flat that afternoon. It was possible, said the prosecutor John Price QC, that a third person was present.

Mr Price said:"It is not possible to state how he died because his body has not been found.

"But whatever happened to Murray Thompson to cause his death in that flat, we do know it was something which caused him to shed a great deal of blood."

"Having killed Murray Thompson, it was James Evans who disposed of his body."

The prosecutor said it was not known what the motive for the killing was, but he said it took place against a background of "serious, organised criminal activity involving the production for commercial supply of controlled drugs."

The two defendants will be sentenced tomorrow.