London (CNN) -- The number of likely victims of phone hacking by people working for Rupert Murdoch's London media empire has jumped to more than 1,000, the top police officer working on the case said Tuesday.
Police have identified another 3,706 potential victims of illegal eavesdropping by journalists in search of stories, Metropolitan Police Deputy Assistant Commissioner Sue Akers told lawmakers.
Authorities had earlier put the number of "likely" victims at around 600, but now say it is 1,069.
They have been investigating the hacking of voice mail by people connected to Murdoch's best-selling Sunday tabloid The News of the World, which was shut down last summer because of the scandal.
Two former editors of the paper have been charged in the case -- including Andy Coulson, who later went on to become communications director for Prime Minister David Cameron.
The other former editor, Murdoch protege Rebekah Brooks, appeared in court Monday.
She, Coulson and six other defendants are due to return to court September 26.
Brooks, a friend of Cameron, was charged in July with three counts of conspiracy to intercept communications.
The most explosive charge against her is plotting to eavesdrop illegally on the voice mail of missing British schoolgirl Milly Dowler, who was later found murdered.
British fury about the news that the missing girl's phone had been hacked forced Murdoch to close the News of the World, which Brooks edited at the time of the hacking.
Suspected hacking victims include some of the world's biggest celebrities, including Angelina Jolie, Brad Pitt, Jude Law, Paul McCartney and soccer star Wayne Rooney, as well as victims of crime and terrorism, politicians and other celebrities.
Coulson became a top aide to Cameron after leaving the newspaper in 2007 in the wake of the first phone hacking arrests, bringing the scandal to the heart of the British political establishment.
Cameron became prime minister in 2010.
Coulson resigned as director of communications for Cameron last year when police launched a second investigation into illegal eavesdropping for Murdoch papers in Britain.
Coulson has always denied knowing about phone hacking, saying he resigned only because he bore overall responsibility for everything that happened at his paper when he was editor.
Brooks, her husband and a former personal assistant also face a separate set of charges of conspiring to obstruct the police investigation into phone hacking. They were charged in May along with Brooks' former driver, a security guard, and the head of News International security with attempting to pervert the course of justice.
The investigation and public notoriety have been damaging to News Corp. and to Murdoch, who stepped down from a string of company boards of directors in July and further distanced himself from the print business that first brought him fame and fortune.
CNN's Jo Shelley, Jonathan Wald and Dan Rivers contributed to this report.