The convictions of Michael Stone for the murder of Lin Russell and her daughter Megan are to be reviewed again by the Criminal Cases Review Commission (CCRC).
The move comes after serial killer Levi Bellfield, who murdered schoolgirl Milly Dowler, is reported to have confessed to the crimes.
The announcement by the CCRC, which comes just three months after a previous review ruled out the case being sent to the Court of Appeal, has been welcomed by Mark McDonald, the long-term barrister for Stone.
The CCRC said in a statement: “Michael Stone’s murder convictions will be reviewed again by the Criminal Cases Review Commission (CCRC) following a request from his representatives.
“In 2001, Mr Stone was sentenced to life imprisonment at Nottingham Crown Court for the murders of Dr Lin Russell and her six-year-old daughter Megan, and the attempted murder of Dr Russell’s nine-year-old daughter Josie, in 1996.
“The CCRC’s previous reviews found no credible evidence or argument that raised a real possibility of the convictions being quashed, these conclusions are not affected by the new review.”
In July, the CCRC said that were was “no real possibility” the Court of Appeal would quash his convictions following a previous review by an independent investigator of potential miscarriages of justice.
A spokesman said: “We have agreed to a request from Mr Stone’s representatives to carry out a further review.
“While we can’t comment on the specifics of an investigation, it is not unusual for different reviews to focus on different arguments or evidence.
“Our commitment to thoroughly investigate all eligible applications extends to undertaking additional work related to cases we have previously reviewed.”
Stone is serving three life sentences for the murders of Ms Russell, 45, and her six-year-old daughter, who were found bludgeoned to death in Chillenden, Kent, in July 1996.
Ms Russell’s other daughter, Josie, then nine, suffered severe head injuries in the attack and the family’s dog, Lucy, was killed.
Last year, Bellfield, who is serving two whole-life orders, claimed responsibility for the murders before later retracting his statement.
In April, lawyers acting for Stone claimed that Bellfield had written and signed a fresh confession to the murder.
Mr McDonald told The Guardian: “Michael Stone has been in prison for 26 years for a crime he did not commit.
“I am really pleased that the CCRC have reconsidered their decision and decided to review this case again.
“It is essential that this review is undertaken as a matter of urgency and Stone’s conviction is referred back to the Court of Appeal.
“The decision as to whether Bellfield is credible needs to be taken by the Court of Appeal, not the CCRC.”
Bellfield was given a whole-life term for murdering Marsha McDonnell, 19, in 2003, murdering Amelie Delagrange, 22, and trying to murder Kate Sheedy, 18, in 2004.
He was already serving his sentence when he went on trial for killing schoolgirl Milly, who was snatched from the street walking home from school in Walton-on-Thames, Surrey, in March 2002.
Bellfield was found guilty of abducting and killing the 13-year-old following a trial at the Old Bailey in 2011.