Loan shark Wonga wriggled free from potential fraud charges yesterday by striking a deal to compensate thousands of customers threatened with fake legal letters. 

Wonga faces £2.6 million in compensation claims after the Financial Conduct Authority (FCA) found it used “unfair and misleading” tactics to chase 45,000 people for debt.

The regulator revealed extra administration charges were piled onto customer’s huge bills for letters from non-existent solicitors threatening legal action. 

But Walthamstow Labour MP Stella Creasy led calls for criminal charges to be brought against the high-interest loans company. 

Ms Creasy said she found it “deeply concerning” that “government regulators have known about this issue since 2011 but it has taken so long for any action.

“Despite these behaviours being potentially a criminal matter under the Administration of Justice Act the police do not seem to be involved,” she added.

But the FCA revealed that it is powerless to take action because the offences took place before the regulator had been set up. 

A spokeswoman told the Star that the FCA could not act retrospectively on misconduct that occurred before it was established earlier this year. 

It said the Office for Fair Trading — the body the FCA replaced — had been responsible for the case before being shut down by the Con-Dem government in April. 

A spokesman for the Crown Prosecution Service also told the Star that the FCA’s hands were tied. 

And tax expert Richard Murphy said it was that the clear the “government has created a clean slate for Wonga.”

The Tax Research UK spokesman said this meant that Wonga had effectively committed fraud and got away with it. 

“It has deceived customers to obtain financial advantage,” he added.

Wonga bosses offered “unreserved” apologies yesterday but campaigners were unmoved. 

Occupy Wonga pledged to ramp up its campaign against the payday lender in light of the revelation with a series of demonstrations against the company. 

“It is criminal what they are doing,” said Occupy Wonga organiser Janie Mac.

She said Wonga’s “intimidation actions are no different from 40 years ago when loan lenders were knocking on council house doors on benefit day.”

Unite Community organiser Liane Groves called on the government to “bring in some proper regulation to stop Wonga “preying on the vulnerable” and “ripping people off” once more. 

Forged legal threats are not the first controversy to hit Wonga. 

Earlier this year the company, which counts the Church of England as one of its main shareholders, admitted to overcalculating balances of more than 200,000 customers. 

In recent months both Wonga’s chief executive Niall Wass and its chairman and founder Errol Damelin have quit the company.