UK (BBN)-The UK government should have known HSBC was helping wealthy clients evade tax in 2010, the whistleblower at the centre of the story has said.
Herve Falciani, former IT worker for HSBC, said UK tax authorities would have known about the stolen list of clients of HSBC's Swiss private bank when it was given to French officials, reports BBC.
It comes as the BBC learned the UK tax authority is to expand its inquiry.
HMRC will meet the police and the Serious Fraud Office later in the week.
Speaking to BBC Radio 4's Today programme, Mr Falciani said French authorities had got in touch with HM Revenue & Customs and passed on information in 2010.
'HUGE ISSUES'
He said the UK government should have known the bank itself was doing wrong in 2010.
"By that time I (had) already declared and explained the problems that were happening," he said.
"It was made public at that time and of course I already at that time explained the major, huge issues we were foreseeing inside HSBC," he added.
Asked if the information Mr Falciani had provided in 2010 was also about the behaviour of the bank, as well as individuals, he said: "It was exactly about the behaviour and containing all the required information for an internal audit."
He said there was much more to be shared and that co-operation between European tax authorities would reveal far more evidence.
His latest revelations follow angry exchanges on Wednesday, when MPs accused tax officials of failing to deal with issues adequately.
Top officials from HM Revenue & Customs were shouted down by MPs, angry at what they said was a lack of urgency in tackling the HSBC tax-dodging scandal.
Margaret Hodge, chairwoman of the Public Accounts Committee, accused Lin Homer, HMRC chief executive, of a "pathetic response".
Ms Homer denied she had failed to take firm action against UK citizens hiding money in HSBC accounts in Geneva.
She said it was "absolutely not the case" she was failing the UK taxpayer.
Ms Homer explained why there had been only one prosecution of someone whose hidden accounts in Switzerland had been revealed.
She said that most of the information leaked via the French authorities in 2010, which involved about 3,600 UK individuals, was incomplete or "dirty" data.
Of these, 3,200 individuals had been traced and, of the 1,100 most serious cases - which HMRC had chosen to pursue - only 130 were now outstanding.
From the rest of those cases, £135m had been recovered, Ms Homer said.
"We were speedy and on the case," she told the MPs.
She explained that in fact, two-thirds of the total group of UK-based HSBC account holders "were found to be compliant" with UK tax rules, in some cases because they had non-dom status.
BBN/SK/AD-12Feb15-2:40pm (BST)