Late submission of accounts to the Companies House

One of my client was subject to HMRC investigation in March 2011 and thus all significant accounting records were picked up from their office. In the absence of material documents I am unable to carry out the audit and despite correspondences to HMRC offices by myself and the company no records have been returned todate.

Do the company have a case for late submission of accounts as matter of extenuating circumstances citing that HMRC holding material facts and figures for us to conduct the audit???

Also, what penalties will be incurred? if any.