I keep thinking about this thread, and wonder what on earth has he spent £42k on ( or 30k if you exclude the original 12k debt). Also, how long has the debt accrued? One thousand a month is approx. 3 - 4 years (depending on which figure you use), or even worse, approx 8-10 months, if you spend £1000 per week.
That’s a lot of dosh. It’s obivously more than a few clothes, even designer clothes. Are there expensive watches, computers, gadgets etc, that he has passed off as work items? Or has others have suggested, drugs, gambling, (or prostitution)?
As a poster above has said, look at the statements now. If they don’t tally, look for evidence of credit cards where he can have hidden online accounts. Or look at his emails and see what transactions he has made.
Don’t listen to his excuses, it’s gone beyond that now. A few hundred, and even a few thousand, but tens of thousands. No!