The police watchdog has been asked to investigate four former and serving senior Metropolitan Police officers over their handling of the phone-hacking scandal.
This includes an allegation that former assistant commissioner John Yates "inappropriately" secured a Scotland Yard job for the daughter of hacking suspect Neil Wallis, a source said.
The conduct of ex-commissioner Sir Paul Stephenson will also be examined. Both he and Mr Yates announced their resignations after coming under intense pressure as the hacking scandal widened.
Five separate issues have been referred by the Metropolitan Police Authority, which oversees Scotland Yard, to the Independent Police Complaints Commission (IPCC).
The IPCC has been asked to look into Sir Paul's actions as the officer with overall responsibility for Scotland Yard's investigation into phone hacking at the News of the World.
It is also considering Mr Yates's decision in 2009 that there was no need to re-open the hacking inquiry and allegations that he inappropriately secured a job for a friend's daughter.
The IPCC refused to give any more details about the details of the referral.
The Metropolitan Police Authority has also asked the watchdog to examine the conduct of two former senior Met officers involved in the original phone-hacking investigation.
It is understood they are ex-assistant commissioner Andy Hayman, who was in ultimate charge of the 2006 inquiry and later become a columnist with News International title The Times, and ex-deputy assistant commissioner Peter Clarke, who oversaw the investigation.
IPCC deputy chair Deborah Glass said: "The role of the Met Police in its original investigation into phone hacking has rightly come under huge public scrutiny. These matters are already the subject of a judge-led public inquiry announced on July 13 which is looking into the way in which police investigated allegations of conduct by persons connected to News International."