LONDON — Adding momentum to police investigations that have already cost Rupert Murdoch’s newspaper empire in Britain hundreds of millions of dollars, Scotland Yard said Wednesday that six more journalists who previously worked for The News of the World were arrested at dawn on suspicion of hacking into cellphone messages.

The latest police swoop followed others in the past year that have resulted in the arrests of more than 100 reporters, editors, investigators, executives and public officials by police units investigating whether criminal activity occurred at British newspapers. Most of those have involved The Sun, Mr. Murdoch’s daily tabloid, and The News of the World, the highly profitable Sunday tabloid he shut down as the scandal broke in July 2011.

In an especially troublesome development for News Corporation, the New York-based parent company of the Murdoch newspapers in Britain, a statement on the latest arrests said they involved “a further suspected conspiracy to intercept telephone voice mail messages by a number of employees who worked for the now defunct News of the World newspaper” — in effect, a new break in the police inquiry, involving possible wrongdoing beyond the wide pattern of phone hacking at the paper that has resulted in 32 arrests so far.

The police statement said five of the arrests on Wednesday took place in London, and one in Cheshire, a county south of the northern city of Manchester. It said those held for questioning were three men and three women, all in their 30s and 40s, none of whom were identified. The Sun later confirmed that two of the six were currently working for the newspaper, having taken jobs there after The News of the World closed. The police said the homes of all those arrested were being searched.