Two lawyers working for News International at the height of the phone hacking scandal are being prosecuted by the legal profession's regulator for allegedly seeking to cover up the scale of criminality at the News of the World.

Lawrence Abramson – who worked for the law firm Harbottle & Lewis, which was hired by the newspaper company – and a former in-house lawyer, Jon Chapman, will come before the solicitors' disciplinary tribunal in October. They are accused of having seen emails in 2007 that proved the widespread use of phone hacking by News of the World journalists but keeping the fact secret and offering false advice to the newspaper company's board.

The two lawyers could now face suspension or be struck off and prevented from practising again. The forthcoming hearing will also be a considerable embarrassment to Rupert Murdoch's newspaper company, which is now called News UK.

James Murdoch, then executive chairman of News International, and other executives repeatedly used as a defence the men's legal opinion that there was a lack of evidence of widespread criminality. The two lawyers, and Harbottle & Lewis, have stressed that the inquiry they were asked to do was narrow and should not have been used to give News International a clean bill of health.

Abramson had been tasked by News International in 2007 with examining a number of emails to find out whether a number of "specified individuals" knew about the illegal activities of News of the World royal editor Clive Goodman after his conviction for phone hacking.

Abramson and Chapman – who was director of legal affairs at News International at the time and also reviewed the emails – came to the same conclusion: that there was no evidence of further knowledge about voicemail interception. However, it subsequently emerged that one tranche of relevant emails that should have been reviewed, and was sent to Abramson, did contain evidence of further illegality.

The disciplinary hearing against the two men will be an embarrassment to Rupert Murdoch, pictured here with former News of the World editor Rebekah Brooks. Photograph: Max Nash/AFP

When that emerged in 2011 the Labour MP Tom Watson made a formal complaint against the men to the Solicitors Regulation Authority, which has been investigating the two men for the past three years. Watson's original complaint, that Abramson and Chapman were under a duty to inform the police if they had come across any criminality, was not valid because there is no such duty. However, the authority believes there are grounds for the lawyers to face the solicitors' disciplinary tribunal over allegations of seeking to cover up the scale of hacking from their clients.

Abramson's defence, according to a source, is that, while he did receive the vital emails, they were given an erroneous subject heading by a temporary secretary and he deleted them without examining their contents. He will further tell the tribunal that Chapman could not have viewed those same emails because he did not pass them on to him.

A source, who said Abramson was interviewed about the case at Christmas 2012 and informed of the prosecution in April 2013, said: "The authority suggests they saw the emails and chose to hide them from the board. And the lawyers say they didn't see them. The emails were sent to Abramson by a temporary secretary on a day when he was out of the office and they were marked completely differently from others of the same nature. It was a day before he was going on holiday. He didn't read it, deleted the email and moved on, he will say.

"Abramson will ask the tribunal to consider whether that is more likely than the authority's case: that he read them, thought they were dangerous, and gave a legal opinion to the board knowing it was wrong. The worst case for the men would be that the tribunal doesn't believe them and believes they are part of a grand conspiracy." A spokesman for the authority confirmed that a case had been brought against the two men, but said it was unable to comment on the charges against them because of "other proceedings".

Last month the Crown Prosecution Service announced that former News of the World deputy editor Neil Wallis and Jules Stenson, a former features editor, were to be charged with an alleged conspiracy to hack phones. They will be charged with conspiring with former News of the World editor Andy Coulson, five other journalists, private investigator Glenn Mulcaire and "other persons unknown" to intercept voicemail messages "of well-known people and those associated with them" between 1 January 2003 and 26 January 2007. They deny the charges. Last week Coulson was formally charged with three counts of perjury at a hearing in Scotland.

In a three-page indictment handed down at the high court in Glasgow, Coulson has been accused of lying about his knowledge of phone hacking at the now defunct Sunday tabloid, lying about his knowledge of the "culture" of hacking at the paper, and lying about his knowledge of payments allegedly made to corrupt police officers while editor of the paper.

The crown claimed that he had lied as a witness in the trial of former Scottish Socialist MSP Tommy Sheridan and his wife Gail in December 2010. Coulson did not attend the hour-long preliminary hearing and did not enter a plea.