Disputed Claims 4.1 Notwithstanding paragraph 4.5 of this Schedule, payment by the Authority of all or any part of any invoice rendered or other claim for payment by the Contractor shall not signify approval of such invoice/claim. The Authority reserves the right to verify invoices/claims after the date of payment and subsequently to recover any sums which have been overpaid. 4.2 If any part of a claim rendered by the Contractor is disputed or subject to question by the Authority either before or after payment then the Authority may call for the Contractor to provide such further documentary and oral evidence as it may reasonably require to verify its liability to pay the amount which is disputed or subject to question and the Contractor shall promptly provide such evidence in a form satisfactory to the Authority. 4.3 If any part of a claim rendered by the Contractor is disputed or subject to question by the Authority, the Authority shall not withhold payment of the remainder. 4.4 If any invoice rendered by the Contractor is paid but any part of it is disputed or subject to question by the Authority and such part is subsequently agreed or determined not to have been properly payable then the Contractor shall forthwith repay such part to the Authority. 4.5 The Authority shall be entitled to deduct from sums due to the Contractor by way of set-off any amounts owed to it or which are in dispute or subject to question either in respect of the invoice for which payment is being made or any previous invoice.