Wirecard, the German payments firm, denounced suspected fraudsters on Friday after $2.1 billion disappeared from its accounts, causing its shares to collapse and cast doubts on the future of the company.

Wirecard's auditor refused to sign off its 2019 accounts earlier this week over the missing money, a disaster that could spark billions of loans being called in as early as Friday.

In an explosive statement on Thursday, the Munich-headquartered card issuer said a total of 1.9 billion euros ($2.1 billion) went missing and that some members of the payments group had intentionally filed misleading statements in order to dupe the auditor and make a wrong perception of the existence of such cash balances.

Wirecard admitted that the accounting irregularity was approximately 25 percent of the company's total balance sheet. Once an epitome of quality in the German tech landscape, Wirecard has been hugely examined over alleged anomalies in its accounting system.

Wirecard's share price plunged 70 percent since early Wednesday. The credit card company had once been among Germany's most respected firms, even surpassing Commerzbank with a 24.6 billion euro ($27.6 billion) market valuation in September 2018.

In an online video post, Wirecard chief executive Markus Braun said that "it cannot be ruled out that Wirecard AG has become the aggrieved party in a case of fraud of considerable proportions," Michelle Martin and John O'Donnell of Reuters wrote, as posted on Yahoo Finance. Braun did not identify those whom he suspected of committing the fraud.

Wirecard dismissed the claims but its failure to win a clean bill of health this week from auditors for its accounts shattered investor confidence, sending its stock into a spiral.

Shares of Wirecard plummeted by over 40 percent as two Philippine banks -- BDO Unibank Inc. and Bank of the Philippine Islands -- said the German credit card group, which is now scrambling to locate the $2.1 billion missing from its accounts, was not a client and claimed that documents had been forged.

Wirecard warned on Thursday that loans amounting up to 2 billion euros could be terminated if its yearly audited report did not see print on Friday. Morgan Stanley market experts estimate that Wirecard has available cash of about 220 million euros, if it cannot figure out where the missing $2.1 billion went.

Wirecard's stock has shed 71 percent since Wednesday's close. The company that was valued at 24.6 billion euros as of September 2018 when it listed on the German Dax index is now worth around 3.4 billion euros.