TODAY, between 9am and 10am, Brian Howes, will visit his local police station in Bo'ness to comply with the conditions of his bail. This evening, between 6pm and 7pm, he will return there once again. Howes must then be home by 8pm, and he will not be allowed to leave his house again until 8am the following day.

Howes is under curfew and these are the strict conditions he has been living under since his release from Saughton Prison, in Edinburgh, last year. There, he spent 214 days on remand. His wife, Kerry-Ann, spent the same amount of time in Cornton Vale, Scotland's only all-female prison, and visits the police station each day between 1pm and 2pm to sign in. Neither of these people have been convicted of a crime. While they were in prison their four daughters were looked after by grandparents.

In a case that once again highlights the controversial impact on Scottish justice of the post-9/11 extradition treaty signed between the UK and the US in March 2003, the Howes are facing extradition to the US on allegations of supplying chemicals over the internet in a conspiracy to produce the drug crystal meth.

The Extradition Act 2003 removed the obligation on US law enforcement agencies to present British courts with prima facie evidence of a suspect's criminality. The US must only provide "written information" relating to an alleged wrongdoing to win an extradition.

While debate raged across Britain last year about the 42-day limit for terrorist suspects, Brian, 44, and, Kerry-Ann, 30, spent seven months on remand. Under the treaty, Scottish timescales which restrict the length of time an accused can be held in custody pre-trial do not apply.

Crystal meth - a form of amphetamine - is a highly dangerous drug that has pervaded the poorer sections of American society for the past 20 years. Psuedoephedrine, iodine and red phosphorus are the three main chemicals require to make the drug.

Howes - an amateur pyrotechnician with experience of handling chemicals from working in a chroming factory - denies that he and his wife, who is now pregnant, broke the law by selling iodine and red phosphorus.

But federal prosecutors at the Drug Enforcement Agency in Arizona allege they were part of a drugs racket supplying a global network of meth labs in the United States, Europe, Australia, New Zealand, and other countries.

Iodine and red phosphorus were just two of about 60 substances the Howeses offered for sale.

The couple insist that red phosphorus is often bought by amateur fireworks fans, and that the iodine they supplied was marked for medical use. Both chemicals are perfectly legal in the UK, but are strictly controlled by the US.

Howes denied that any of his products were intended for underground crystal meth manufacturing labs. He said: "We were in a legitimate business registered with the Home Office and the Health and Safety Executive.

"The US says on the indictment that we were supplying crystal meth labs, but it's absolutely ridiculous to suggest that some chemicals we were selling in the UK were being sold to drug dealers.

The Health and Safety Executive in Edinburgh confirmed it had inspected Howes's business premises on several occasions and only expressed concern over the way he stored chemicals.

However, because of the extradition deal in place with the US, no Scottish court will ever hear his arguments.

The Howeses were released in August 2008 after Brian spent 30 days on hunger strike. The result is that his speech has been affected and he may have suffered brain damage.

The couple are waiting on a final high court appeal that could see them taken to a prison in the Arizona desert to await trial. They may have to wait up to three years before their case is heard. Kerry-Ann, diagnosed with chronic post-traumatic stress disorder, and their girls - Leela, two, Ellie, five, Bethaney, nine, and Denni, 11 - will have to go into care if the extradition goes ahead.

Howes, who also has two other children, Ryan, 12, and Jessica, eight, from another relationship, warned that the effects of being separated from their children could drive the couple to suicide.

He said: "The effect on the kids has already been traumatic. I used to phone them up from prison and they couldn't cope without it. It has been horrible.

"We have told all the kids that if we go to America there is a terrible possibility we may never come back. My kids are my life. If we had to go to that prison in Arizona, I know my wife would die and I would die shortly afterwards."

A conviction for unlawful importation of regulated chemicals carries a maximum sentence of 20 years' imprisonment and a fine of up to $250,000.