Deloitte's firm in China is seeking to block attempts by US regulators to obtain audit work papers, saying the documents may be released under a deal struck last week between China and the Public Company Accounting Oversight Board (PCAOB).

In court, lawyers for Deloitte Touche Tohmatsu argued that the Securities and Exchange Commission (SEC) has 'alternative means' to get the documents. The SEC is seeking the information as part of its fraud investigation of Deloitte client Longtop Financial Technologies Ltd, according to Reuters.

In September 2011, the SEC asked the federal district court in the District of Columbia to enforce a subpoena, it sent Deloitte, in connection with audit work it performed for Longtop.

Longtop was charged by the SEC two months later with failing to file timely financial reports, and the SEC has said it suspects the company of committing fraud.

Deloitte's application to the courts comes a few days after the PCAOB and regulators in China struck a deal on mutual access to audit papers of firms in China and the US that audit companies across both jurisdictions.

In their argument, Deloitte's legal team said: 'This provides the SEC with an additional alternative means to obtain and use the documents requested in its subpoena here - that is, directly from the PCAOB.'