A police commissioner has claimed that bosses at Lloyds and HBOS contrived to cover up a banking scandal that cost the bank's customers millions.

In exchange for bribes and gratuitous favours, Lynden Scourfield, a former manager at HBOS' Reading branch, and his associates told customers to use turnaround consultants Quayside Corporate Services, which subsequently defrauded those sent their way.

Businessman Michael Bancroft and David Mills, who ran Quayside, arranged sex parties attended by porn starlet Suzie Best and other high-end escorts for Scourfield, while exotic foreign holidays, cash bribes and other favours in kind followed between 2003 and 2007.

Their lavish lifestyle earned them the nickname of "Britain's Wolves of Wall Street", in reference to Jordan Belfort, a former US trader who was made famous by the 2013 blockbuster movie in which he was played by Leonardo DiCaprio and directed by Martin Scorsese.

Lloyds was not in control of HBOS when the fraud unfolded and has maintained it is itself a victim in the circumstances, but Thames Valley Police's commissioner Anthony Stansfeld has have claimed the banking giant knew about the scandal as early as 2008.

Stansfeld said senior executives at Lloyds deliberately chose against contacting the police for fear of bad publicity. Eric Daniels and Sir Victor Banks, respectively chief executive and chairman of Lloyds at the time have always suggested they were unaware of any wrongdoing. However, Stansfeld disputed the theory, saying he has an internal email which proves the bank's top executives were indeed aware of the scam.

"The cover-up went on for 10 years,' Stansfeld said on Saturday.

"An internal email in February 2008 within the risk department of HBOS clearly says that a major fraud had taken place within the Reading branch of HBOS, and that at least £200m had been defrauded from HBOS customers.

"Yet despite this evidence, the board of Lloyds [...] continued to refuse to accept that a fraud had taken place and pursued the victims."

Stansfeld also stated the cover-up only surfaced thanks to the victims and a few whistleblowers, who worked for the bank and who, he alleged, were subject to "disgraceful treatment" by the banking giant.

The FTSE 100-listed bank, which has previously been asked to review its handling of the fraud and publish its findings, has set aside £100m to compensate the victims but Stansfeld said the figure was not large enough.

In February, in an open letter to the lender's chief executive, Antonio Horta-Osorio, and its chairman, Lord Blackwell, MPs on the All-Party Parliamentary Group on Fair Business Banking called for the banking giant to offer compensation to the victims.

Kerevan added the complaints of the "criminal activity were raised with senior HBOS management at board level and as early as 2007" and were repeated to senior Lloyds management after the takeover.

"In both instances, there was an internal failure to adequately investigate these complaints," he said.

"Further, police investigations were delayed because both HBOS and subsequently Lloyds informed the authorities that it was the bank that was the wronged party – rather than small business customers – but that the bank had no wish to pursue a prosecution."

A few days earlier, Scourfield, Bancroft, Mills and his wife, Susan, along with consultant John Cartwright and former HBOS banker Mark Dobson had been slapped with hefty custodial sentences at a hearing in London's Southwark Crown Court.

Scourfield, who pleaded guilty to six counts including corruption, was jailed for 11 years and three months.

David and Allison Mills, received 15 years and three-and-a-half years in jail respectively, while Bancroft was jailed for 10 years and Cartwright got three-and-a-half years for their convictions on counts including bribery, fraud and money laundering.

Dobson, meanwhile, was given four-and-a-half years.