Legal query

[#1]

We know a couple who run a small business and employ people on self employed system, seems one guy working for them was going to the local garage with one of their vans filling it with diesel and then filling a few cans in the back of the van for his own use.
The garage assistant knew the owner of the business and as the whole thing was on video the guy was sacked for theft and reported to the Police, however up to the point of his dismissal he was owed around £700 in wages for work done and this this has been withheld. No idea how much fuel he stole but it would have to be a lot to match the £700.
The question is, does the employer have a right to refuse to pay this money or withhold it until after a court appearance  assuming the chap actually ends up in court ?

[#2]

My advice  FWIW is to suggest "the guy" sacrifices the £700 in exchange for the small business owner not pressing charges.
Don''t think you can 'sack' a self employed person, you can choose not to offer them further work and if the existing work is not up to scratch can withhold payment.

[#3]

Had it been salary to an employee the employer would not have been allowed to withhold the payment. As the payment was for self employed duties the business owner has a right to withhold it. The self employed contractor of course would have the right to challenge this in the courts.