Security checks corporation tax refund

We’ve had a repayment removed from our online corporation tax screen. On querying why it was removed and not sent as a repayment, HMRC state; “The submitted claim requires additional security checks. We will write out to request further information if needed. This will be in the next 2-3 weeks, please do not send progress related emails in this time.” Can anyone shed and light on what these additional security checks might be?

Hi Checks on repayments are regularly applied to ensure accuracy, appropriate legislation has been adhered to and that there has been no fraudulent activity. Thank you

Yes the idea of checking things especially to counter fraud is fully appreciated and expected but what is unusual is that HMRC give no specific details as to how long such checks will take and neither give any indication they are happening (a value vanishing from an online account tells the end user nothing resulting in phone calls to HMRC) or any indication of what may be required in order to release the payment and when looking at a 6 figure sum, whilst fully appreciating your need to protect the public purse, this is an amount that is fundamental to our continued existence as a revenue generating tax payer.