said that Ernst & Young, which audited Swindon-based Farepak's and EHR's accounts for the year to April 30, 2005, is not under investigation.
The AIDB investigators are likely to look in particular at accounting irregularities at Transbus, which Mayflower announced in March.
The AIDB can seek to impose unlimited fines on firms or individuals or to have them expelled from the profession's representative bodies.
Robson Rhodes also said it would fully cooperate with the AIDB.
The AIDB and FSA inquiries come after an internal investigation at iSoft found evidence of financial irregularities.
In response, PwC said: "We are surprised that the AIDB has chosen to file disciplinary complaints against this firm.
Disciplinary complaints filed following an AIDB investigation are heard by an independent tribunal.
A spokeswoman for PwC said: "We are surprised the AIDB
has chosen to file disciplinary complaints against this firm.
The inquiry will be the first by the AIDB
since it was created in May as part of a new independent accountancy regulator, the Financial Reporting Council.
The investigation into the Mayflower Corporation will be the first since AIDB
was created last May as part of new independent accountancy regulator the Financial Reporting Council.