A British engineer murdered in the French Alps a year ago recorded all of his phone calls giving police "some very precise details."
Ten months after his brother's murder in the French Alps, Zaid al-Hilli has moved from witness to suspect.
Two British girls who survived the killings of their family in the Alps are to be interviewed by police as the search for answers continues.
Speaking to reporters outside his home in Surrey, Zaid al-Hilli said it was "good news" that he would not be charged in connection with the murder of his brother and that he was "relieved".
Surrey Police said they would continue to work with French authorities on the investigation.
A statement added:
The 54-year-old man, from Chessington, was arrested on 24 June 2013 on suspicion of conspiracy to commit murder and interviewed as part of the on-going investigation.
At this stage there is insufficient evidence to charge him with any criminal offence and no further police action is being taken at this time.
Saad and Ikbal Al-Hilli from Claygate, Surrey and her mother Suhaila al-Allaf, who lived in Sweden, were found shot dead along with French cyclist Sylvain Mollier on a remote forest road in Chevaline on September 5 2012.
This remains a French-led investigation and officers from the Surrey and Sussex Major Crime Team continue to work closely with the French authorities.
We have carried out exhaustive enquiries in the UK on a number of active lines of enquiry under the terms of the Joint Investigation Team (JIT).
Zaid al-Hilli, who was accused of orchestrating the shooting of his brother Saad al-Hilli, his wife and mother-in-law, has had his bail cancelled because there is not enough evidence to charge him with a crime, police said.
French police have released a sketch of a man wanted for questioning in connection to the Alps murders of British-Iraqi Saad al-Hilli, his wife and her mother, in September last year.
A French cyclist was also shot dead. Mr al-Hilli's two daughters survived the attack on a remote road near Lake Annecy.
Investigators quoted on the Le Monde website stressed that attention should be paid to the dark or black helmet worn by the motorcyclist with an opening at the chin.
The brother of the British businessman murdered in the French Alps with his wife and mother-in-law has said in his first interview that he is not the killer.
Zaid Hilli, 54, who is on police bail following his arrest on suspicion of masterminding the murders 13 months ago, told the Sunday Times (£) that Saad al-Hilli grabbed him as they argued about their inheritance.
However, he denied any involvement in the shootings that killed Saad, 50, his wife Ikbal, 47, his mother-in-law Suhaila al-Allaf, 74, and Sylvain Mollier, a French cyclist. The al-Hillis’ daughters, Zeena, then 4, and Zainab, then 7, survived the attack.
“The French, I don’t trust them at all. My brother was killed there in that region and I am not going to take the risk. If they wanted to come over here, that’s fine,” he said.
One of the victims of the French Alps murders recorded all of his phone calls giving police "some very precise details", investigators said today.
British engineer Saad al-Hilli recorded all of his telephone calls and the audio files are in the process of being analysed.
Mr al-Hilli, his wife Iqbal, her mother Suhaila al-Allaf and French cyclist Sylvain Mollier were all killed in the attack on September 5 last year. The al-Hillis' daughter Zainab was shot in the shoulder and beaten, but survived.
French and British investigators held a joint press conference today, where Annecy prosecutor Eric Maillaud said: "The victim recorded all his telephone conversations. We therefore have some very precise details."
He added that although no charges have been brought in the case, police "have made great advances."
British and French police said they were "determined" to solve the murders of three al-Hilli family members and a French cyclist which took place a year ago.
Saad al-Hilli, his wife Iqbal, her mother Suhaila al-Allaf and Sylvain Mollier were all shot dead in the French Alps on September 5 last year. The daughters of Mr and Mrs al-Hilli survived the attack.
Mr al-Hilli's brother Zaid, who is due to answer police bail next month, was arrested on suspicion of conspiracy to murder amid claims he changed documents to ensure he inherited their father's inheritance.
Police said their main line of inquiry remains a row over inheritance, with Annecy prosecutor Eric Maillaurd saying: "This is being followed up actively."
Mr Maillaurd added that the two brothers "initially worked together to regain their father's property" in Iraq but differences between the men soon emerged, according to news agency AFP.
The brother of a British engineer who was shot dead with his wife and mother-in-law in the French Alps has been bailed after being arrested and questioned by police.
Zaid Hilli was arrested yesterday on suspicion of conspiracy to commit murder after officers uncovered evidence to suggest he doctored documents to ensure he inherited the estate.
Hilli, 54, has previously denied any feud with his sibling over an inheritance or involvement in the killings.
A police spokesman said: "The 54-year-old man who was arrested yesterday on suspicion of conspiracy to murder has tonight been released on bail until July 31 pending further enquiries."
Detectives investigating a multiple murder in the French Alps last September, including a British couple, have arrested the brother of one of the victims.
French and British police have been working together to find the killer of Saad Al-Hilli, his wife, his mother-in-law and a French cyclist.
ITV News Europe Correspondent Emma Murphy reports.