Loan interest payable

Hi,

I lent some money to an LLP and they are paying me interest on this loan, only they are deducting tax at source on this money. Please could someone tell me if this is correct? I was of the belief that these payments should be made gross and I would then account for the tax directly once I complete my tax return. I would be grateful if you could supply me with any statutory references you know of regarding this.

On a separate note, I have also borrowed money from a private investor, who I am paying interest to. Do I therefore need to deduct tax at source from the interest payments that I am currently making to him? Again any hmrc reference would be useful.

Thanking you all in advance.