Talos has filed a cross-claim alleging the vendor breached the sale contract by approaching clients of the accountancy firm and "falsely billed clients for services that were not provided".
Philip Stroud, lawyer for FAM, said he believed the cross-claim had no merit, was "filed to delay the proceedings and in an attempt to frustrate our client's legitimate and strong claim against Talos." "No supporting particulars or evidence have been supplied in support of the allegations," he told the Weekend Herald.
Neither Bryers nor Stephen Lacy - who is listed as the sole director and shareholder of Talos - responded to requests for comment.
Earlier this month Mr Mandelson told the Herald that Talos paid an initial deposit for his accountancy firm, Rick Mandelson and Associates, but defaulted on the first instalment.
Talos had presented a property investment scheme to be pitched to the accounting firm's clients. According to a source, Talos aims to acquire 100 small accountancy firms, achieve a turnover of $300 million and launch on the Australian stock exchange in three years.
Australian authorities are investigating complaints that Talos group has not honoured debts and tax obligations.
Bryers, who is seeking to be discharged from bankruptcy, said in a statement this month that he had never been a shareholder or director and worked for the company "as a consultant via my employer".
He has told the High Court at Auckland, which is next month due to hear his application to be released from bankruptcy, that his employer was Australian company Forsite Marketing Pty Ltd. Official filings show that Forsite and Talos share offices and have the same listed director and shareholder, Stephen Lacy.