Dissolved company debtor

A old debtor of my limited company was billed in September 2011 just before the company was dissolved.
It was calculated that in total he owed £98,000 and it appeared that at the time there was little prospect
of him ever having enough assets to cover the debt plus he never replies to my letters. Because of this debt
I have been left very short of money to be able to sue or bankrupt him. I have just served him with a
statutory demand for £11,000 and he has applied to have it set aside because I was convicted, of fraud, of tring to
get back some of the debt by an alternative method. On dissolution of my company I transferred the full debt to my
new business run as a sole proprietorship. The debt is legitimate and can be fully backed up with paperwork and invoices
paid out by me personally. If I never receive payment of part or all the debt have I got a legitimate bad debt relief
claim which I can set off against my current businesses profits which are going to be approx. in the region of £15,000.
After all the bother I have had for the last four years witj the police and courts and prior to that for three and a
half years when my ex business partner kept me living like a pauper whilst doing ninety percent of the work for
our joint business I do not now want a tax investigation into my current tax affairs. Some of my current earnings are still being used to pay off borrowings I took on, six years ago, to keep the joint business, run by me and my ex business partner, afloat.