• Video report by ITV News Consumer Editor Chris Choi

TSB chief executive Paul Pester has apologised repeatedly to customers who suffered fraud as a result of the IT problems that caused chaos for the bank as he was grilled by MPs for the second time.

His latest appearance comes as it was confirmed the financial regulator was investigating the bank's IT meltdown that left millions locked out of their accounts and in some cases saw their life savings stolen.

This is what we learnt during the parliamentary session.

  • The scale of the problem revealed

One of the biggest fallouts from the meltdown was how easily it was exploited by criminals.

Boss Paul Pester told the committee 1,300 customers suffered financial loss due to fraudsters, there were 2,200 actual attempts at frauds and 10,600 "fraud alerts".

In some cases life saving have been stolen from customer accounts.

The bank are still wading through the problem but are, at times, only able to answer one in 10 customer calls about fraud due to the huge volume of complaints.

In a letter addressed to Ms Morgan, Dr Pester revealed TSB had received 95,613 complaints from customers as a consequence of the IT migration.

He said they were working as quickly as possible to resolve the problems, but only 24,094 - about 25% - have so far been resolved.

Dr Pester said "the level of (fraud) attacks went up 70%" and, according to ITV News Consumer Editor Chris Choi, admitted during his grilling that some customers had been kept waiting for as long as five hours on the TSB helpline.

A "significant volume of staff" will be brought in within the next week to deal with outstanding complaints and banking officials told the committee they expect TSB to widely publicise a compensation scheme.

Dr Pester admitted 12,500 customers have switched away from TSB since the meltdown, adding he did not know why.

When asked how much money was being put aside to sort the problems out, TSB chairman Richard Meddings said around £50 million had already been paid out to customers in fee waivers, compensation and/or in fraud refunds.

He said: "And if you want the rest of the cost number... in addition to that the incremental resources that the group has been bringing on... it's around another £20 million. So year to date it's about £70 million."

  • Dr Pester would like you to know he is VERY sorry

The TSB boss apologised repeatedly as he appeared before the committee.

Asked if he should take responsibility for many committee members feeling the way he had communicated to them was misleading, he answered: "I'm deeply sorry if you feel I have misled the committee. There is nothing that I've said that has not been said in good faith."

Asked if he was trying to make the fraud numbers appear more insignificant, Dr Pester said: "I'm deeply apologetic if you believe that I am in some way trying to spin the information."

On the issue of fraud, he said: "We were overwhelmed. We saw a 70 times uplift in cases reported. I obviously apologise profusely for this."

Dr Pester admitted some customers have waited five hours on the TSB helplines for which he apologised "unreservedly".

So numerous were Dr Pester's apologies, that MP John Mann said, in response to a couple who were given £100 compensation for payment problems wrecking their wedding plans, that it was "a pound per apology".

Mr Mann's constituents Chris Portlock and Toni-Marie Becher had their wedding plans wrecked by payment problems.

Mr Portlock told ITV News that the amount paid in compensation was not "nearly enough" to make up for the major effect the bank's meltdown had on their big day.

  • Why is TSB being investigated?

In April, up to 1.9 million people using TSB’s digital and mobile banking found themselves locked out of their bank accounts following the migration of data on customers from former owner Lloyds’ IT system to a new one.

The Financial Conduct Authority (FCA) is now investigating TSB’s troubled IT migration as Treasury Committee chairwoman Nicky Morgan warned she was “deeply concerned” about how problems were communicated.

Andrew Bailey, chief executive of the FCA, said: “We do not normally make this information public, but, given the level of public interest, I want to be clear that we will be conducting this work."

Richard Meddings, Paul Pester and Miquel Montes answered questions from MPs. Credit: ITV News
  • What has been TSB's response before today been?

Unsatisfactory, according to Andrew Bailey who in an earlier letter to Ms Morgan said the watchdog "had concerns that TSB was not being open and transparent about the issues experienced.”

During Wednesday's session, MPs called the bank's compensation policy "cringe-worthy".

While Mr Bailey said the bank had been "overwhelmed" by the problems and were not reimbursing customers fast enough.

He did add that they were now "back on track".

A "significant volume of staff" will be brought in within the next week to deal with outstanding complaints and banking officials told the committee they expect TSB to widely publicise a compensation scheme.

  • Does TSB know the cause of the IT problem?

The FCA official told the committee that "understanding was still emerging".

In other words: no.

As the investigation rolls out, fingers of blame will be pointed and as Dr Pester told MP John Mann "where there is culpability we will act".

  • Are other banks at risk?

FCA chief said he "couldn't rule it out".

TSB chief executive Paul Pester's response to the trouble has been questioned. Credit: TSB online problems

In her closing remarks Ms Morgan says unfortunately the saga goes on as a letter from the FCA said TSB had failed to be open and transparent and warned the panel "we will be keeping a very close eye on what is going on to put all of this right."