Channel 4 News has learnt that two more high-profile companies have pulled advertising from the News of the World following revelations about phone hacking.
Specsavers has withdrawn its adverts from the News of the World following allegations that the paper hacked in to the mobile phones of the victims of terrorism and serious crime.
Group marketing director Richard Holmes said: "I have decided that given the situation at the News of the World, we will not place any more advertising with them until further notice."
Channel 4 News has also learnt that Alliance Boots is taking action after the latest revelations.
The company said in a statement: "In light of the evolving situation, we have put on hold further advertising with the News of the World. An advertisement, which was printed some time ago, however, will appear in this Sunday's Fabulous magazine."
The Daily Telegraph claimed the phone numbers of relatives of dead service personnel were found in the files of private investigator Glenn Mulcaire, who was jailed in 2007 for phone hacking members of the royal family.
A number of other firms have already distanced themselves from the News of the World including npower, Halifax bank, Virgin holidays, the Co-operative Group, Vauxhall and Mitsubishi.
Police to investigate Sheridan trial
In a separate development Strathclyde Police have been asked to look at evidence given by witnesses during the Tommy Sheridan perjury trial in light of recent allegations about phone hacking at the News of the World.
Andy Coulson, David Cameron's former director of communications, was among those who gave evidence.
Channel 4 News' Political Editor Gary Gibbon asks where the hacking saga will lead?
"For some time, Andy Coulson's friends have said that the Tommy Sheridan trial was the moment he realised he had to leave his job as Head of Communications at Downing Street.
"A whole week last December was given over to non-Government business..."
Read more: Coulson evidence adds twist to NotW saga
Mr Coulson told the trial last December that he had no knowledge of illegal activities by reporters while he was editor of the newspaper.
He also told the trial: "I don't accept there was a culture of phone hacking at the News of the World."
When asked by Sheridan, who was conducting his own defence in the trial, whether his newspaper had made payments to police officers, Mr Coulson answered: "Not to my knowledge."
Sheridan was jailed for three years in January after being found guilty of perjury during his 2006 defamation action against the News of the World.
He successfully sued the newspaper over claims that he was an adulterer who visited swingers clubs, but was later charged with perjury and convicted following a three-month trial at the High Court in Glasgow.