It is not only smoking cannabis that can get you in trouble with the law, writing about it can prove to be an even more serious offence, writes Graham Ball.

In 1994 Mick Marlow, who lives in Gloucester, wrote and published a book on how to grow cannabis plants at home. Tricameral Sinsemilla described a technique that enabled growers to rotate their crop in such a way that it is possible to harvest once a fortnight.

He placed a series of advertisements in magazines and sold 500 books at pounds 13 each by mail order. A reporter on the Worcester Evening News spotted Mr Marlow's small ad in Private Eye. The advertisement requested readers to send their orders to a PO box in Worcester.

"Do the people of Worcester want this trade in their county?" thundered the paper. Mr Marlow's book was acquired by the police, who forwarded it to the Crown Prosecution Service. "Our home was raided, Mick was arrested and the police confiscated the unsold copies of his book," said Mrs Angie Marlow.

Mr Marlow was charged with inciting others to grow cannabis. The jury found him guilty and the judge sentenced Mr Marlow, who is 53, to a year in prison, despite the fact that he has been registered disabled since 1975, suffers pain from back and leg injuries, and is diabetic.

"We were devastated at the severity of the sentence," said Mrs Marlow. "There are dozens of items that are openly sold that could equally be said to incite the use of cannabis, from cigarette papers through to special growing kits."

Although Mr Marlow is out of prison, his battle with the law goes on. Liberty, the civil rights group, is fighting for the return of the confiscated manuscript of another (unpublished) book on cannabis growing. "My husband dares not resort to cannabis to relieve his pain and is afraid he is becoming hooked on the drugs the doctor provides," said Mrs Marlow.