With the Libor scandal already having numerous tentactles, don’t expect it stop growing anytime soon. In a new story by the Wall Street Journal, it appears that emails may be the catalyst for growth.

In a story by Jean Eaglesham, David Enrich and Paul Vierira, traders’ emails and instant messages pushed Barclays PLC (NYSE:BCS) into settling for $435 million with regulators last week for interest-rate manipulation. But the investigation isn’t over yet for regulators as they are looking at 16 additional banks and financial institutions for three criminal and 10 civil investigations. This extends across North America, Europe and Asia, reported the Wall Street Journal.

Before deciding whether or not regulators will charge the banks for meddling with interest rates, regulators will continue their investigation through reviews of internal communications. In the upcoming months, there could be additional settlements by the banks.

Along with regulatory pressure, the banks have also been named as defendants in U.S. private class-action lawsuits. The Wall Street Journal reported that a plaintiffs’ attorney for one case said they will attempt to depose the banks’ chief executives that have been accused of  rigging interest rates. This includes Barclays PLC’s former CEO Robert Diamond, who resigned on Tuesday.

He has denied any wrongdoing at the bank.

With the numerous lawsuits, look for a big payday of potentially billions of dollars said Hilary Scherrer, a partner at law firm Hausfeld LLP who is defending plaintiffs for one of the lawsuits.

Regulators also believe they have a strong case. Bart Chilton, a Commodity Futures Trading Commission commissioner said to the Wall Street Journal, “Nothing could make the case more powerfully for forthright regulation than what the bankers themselves have done.”

For the CFTC, its case is not new. They began an investigation in May 2008 after Wall Street Journal story posed questions about the the Libor’s integrity.

CFTC officials had thought Barclays was a good choice for the first of many settlements because the bank did agree to admit  its executives and traders tried to manipulate Libor and other benchmark rates.

With Barclays admission, it has a deal with the Justice Department that will not prosecute the bank as opposed to the usual settlement with civil regulators that leaves a company neither admitting nor denying wrongdoing.

So what’s next?

Some regulators from different countries are receiving help from Barclays and UBS AG (NYSE:UBS). The Swiss bank has made immunity deals in the U.S., Switzerland and Canada. This will protect it against enforcement action for some transactions and submissions, reported the Wall Street Journal.

Court documents have also shown that UBS AG has given the Canadian Competition Bureau numerous potentially damaging documents including emails, instant-message transcripts and trading records.

Traders from different firms are also under review; most have either been suspended or fired from their jobs.

This month, the U.K. Serious Fraud Office will make a decision whether to bring criminal charges. And the U.S. Justice Department is conducting a criminal investigation against traders both at Barclays and additional banks.