Repaying R&D Monies During Investigation

A company I work for was granted R&D tax relief earlier this year, and the monies were transferred into their account.
We then received a letter to advise the claim was under investigation and we needed to send supporting paperwork. This was then rejected (with no details as to why) and it was requested that we pay back the initial relief monies.
Guidance was also given on how to appeal, which we have.
My question is does the money need to legally be paid back to HMRC by us whilst the investigation is ongoing, or can we await the outcome?
It has now been over a month since the appeal process started and we haven't received any further requests for repayment, or any updates on the appeal investigation.
Any advice would be appreciated.

Hi
As stated at the top of this Forum we have no access to R&D claims nor can progress chase or provide advice.
This forum is for general queries only and is intended to help you self-serve. 
The correspondence you have received will detail the next actions you must take and the contact details for further information. 
If the company has any concerns regarding their claim or the reasons for the investigation, they should seek professional help from a reputable R&D agent. 
Thank you