City of London Police said in a statement:
In March 2013 the Office of Fair Trading (OFT) met with the City of London Police to consider their (OFT's) investigation into Wonga and whether it should be referred to the National Policing Lead for Fraud.
The interests of the consumer were at the forefront of these discussions and directed the decision that the most appropriate course of action was for the OFT to continue to investigate as regulator focusing on but not limited to the consumer credit act, legal services act, and unfair trading regulations.
Now that the regulator's investigation has concluded and a compensation agreement has been reached with Wonga, the City of London Police will be reassessing whether a criminal investigation is now appropriate.
City of London Police have confirmed they are to look again at whether they think a criminal investigation into Wonga would be appropriate after the payday lender sent out fake legal letters to customers.
Solicitors across England and Wales are pressing for Wonga to face a criminal investigation over fake legal letters it sent to 45,000 customers.
Britain's biggest payday lender has agreed to pay £2.6 million compensation over the "misleading debt collection practices," but the Law Society wants the Metropolitan Police to investigate and consider whether any offences, such as blackmail or those under the Solicitors Act, have been committed.
Law Society chief executive Desmond Hudson said: "It seems that the intention behind Wonga's dishonest activity was to make customers believe that their outstanding debt had been passed to a genuine law firm.
"It looks like they also wanted customers to believe that court action undertaken by a genuine law firm would follow if the debt was not repaid."
The Financial Conduct Authority said that it referred Wonga to the police to assess whether the payday lender had committed a criminal offence, but the City of London Police have decided not to proceed with a case, ITV News Editor Jess Brammar has learned:
We're told Wonga case was referred by the regulator to City of London police for consideration. We understand police decided not to proceed.
Wonga is Britain's biggest and best-known payday lender. In an industry that has a terrible reputation, Wonga has always maintained that it was somehow different.
We now know that between 2008 and 2010 it was sending threatening letters to customers in arrears from law firms that didn't even exist.
In some cases they levied administration fees of up to £400,000.
Wonga is paying compensation - but it has not been fined.
The regulator is a new one, the FCA has only been around for three months and doesn't have the power to impose fines for things that happened four years ago.
But we do know that the regulator has asked the police to assess whether criminal proceedings should continue because it is illegal to impersonate a solicitor.
The Financial Conduct Authority said that it has referred Wonga to the police to assess whether the payday lender had committed a criminal offence by sending letters from fake law firms in order to pressurise their customers into paying back loans.
ITV News Business Editor Joel Hills reports:
It is illegal to impersonate a solicitor. @thefca confirms has referred Wonga's case to police to assess if legal action should follow.
Labour MP Stella Creasy, a fierce campaigner against payday lenders, said that Wonga's apology over its misleading practices "isn't good enough."
She said: “Today's news that Wonga were sending fake solicitor letters to cash strapped customers who couldn't afford their fees to frighten them - and charging them for these - is further proof of the need for Britain to rid itself of these legal loan sharks.
"It is also deeply concerning the Government regulators have known about this issue since 2011 but it has taken so long for any action, and that despite these behaviours being potentially a criminal matter under the Administration of Justice Act the police do not seem to be involved.
"Local debt collectors who behaved in this way wouldn't get off so easily, so we urgently need to know why Wonga isn't being held to account when they admit to flouting the laws on harassing debtors - saying sorry four years later just isn't good enough."
A Church of England spokeswoman, commenting today on the FCA ruling that Wonga had engaged in "unfair and misleading debt collection practices" said:
We welcome anything that clamps down on aggressive or irresponsible debt collection practices, and not just by payday lenders.
This highlights the need for more responsible alternatives to payday lending and other forms of high cost credit.
That is why the archbishop's task group is developing a set of practical initiatives to meet the need for more affordable and responsible lending and saving opportunities.
The Church of England, which has indirect investment in payday lender Wonga, said that it "welcomes anything that clamps down on aggressive or irresponsible debt collection".
ITV News Business Editor Joel Hills reports:
Church of England "welcomes anything that clamps down on aggressive or irresponsible debt collection". CoE has indirect investment in Wonga
Wonga is a private company but Church of England has "less than £100,000" invested via private equity investment trust.
Church estimates cost of getting rid of its "exposure" to Wonga immediately at between £3 million and £9 million.