UPDATE: The suspected bombmaker in the Paris attacks has been identified as one of two suicide bomberswho died in the Brussels airport blasts, a U.S. official told CBS News, citing Belgian police sources.

Najim Laachraoui's DNA was verified as that of one of the attackers on Tuesday, after samples were taken from remains found at the blast site in Brussels airport, the officials said.

Authorities are still searching for one of three men captured on airport security footage prior to the deadly bombing. His identity has not been released by police.

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BRUSSELS -- Two of the suicide bombers who targeted Brussels Airport and the city's subway system were identified Wednesday as Belgian brothers Khalid and Ibrahim Bakraoui, and there were brief, though ultimately false hopes that an ISIS bomb-maker possibly linked to the attacks had been apprehended.

A major Belgian newspaper and television network reported early Wednesday that police had taken Najim Laachraoui, the Belgian national suspected of making the bombs for the Nov. 13, 2015, attacks in Paris and yesterday's carnage in Brussels, which left at least 31 people dead, into custody.

Officials never confirmed the reports, however, and the media outlets later said the man arrested in the southwest Brussels district of Anderlecht on Wednesday had not yet been identified.

Later, Belgium's federal prosecutor indicated the person arrested Wednesday in Brussels was not Laachraoui. The suspect seen with the two suicide bombers at the airport, widely reported to have been the bomb-maker, did not detonate his own bomb at the airport, the prosecutor said, and was still on the run.

Laachraoui's arrest would have been a major blow against what appears to be a deadly ISIS cell in Western Europe. But as worries over the Belgian authorities' ability to tackle the home-grown threat mount, the information emerging Wednesday also suggested a fourth, still-unidentified assailant.

There was no information available about the man seen on the left-hand side of an image from an airport security camera released Tuesday. Ibrahim Bakraoui appears in the middle of the image (seen above), and Belgian and other European media have said the man on the right is believed to be Laachraoui.

The Bakraoui brothers had a long history of crime and were known to authorities, but had not been linked to terrorism before last week.

RTBF said Khalid El Bakraoui rented the apartment in the Forest neighborhood of the Belgian capital, using a false identity, that was raided by police last Friday in an operation that led to the arrest of top Paris attacks suspect Salah Abdeslam.

Brothers Khalid and Brahim Bakraoui, suspects linked to the Brussels terrorist attacks, are pictured on a newspaper front page in Brussels, March 18, 2016. CBS

Khalid was given a five-year prison sentence in 2011 for armed robbery and car theft, according to French newpaper Le Monde. Brahim was sentenced to nine years in prison for opening fire on policemen using a Kalashnikov during a burglary in 2010, according to Belgian newspaper DH.

Laachraoui, 25, has been openly sought by the police since Monday and it is believed he may have built the bombs for both the Brussels attacks and the Paris carnage in November.

CBS News correspondent Charlie D'Agata reported that, according to Belgian authorities, Laachraoui's DNA was found on the explosives used in the gun and suicide attacks in Paris, which left 130 people dead. He was already Europe's most-wanted man when he walked into Brussels Airport on Tuesday morning.

The Belgian federal prosecutor's office said Wednesday that a laptop found during a Tuesday raid of the Schaerbeek area of Brussels contained an apparent last will for Ibrahim Bakraoui, one of the airport bombers. The note apparently mentioned Bakraoui feeling increasingly paranoid and worried about ending up in prison.

The November attacks in Paris is believed to have been planned in Brussels, where a handful of the attackers lived or had links. That attack was blamed on ISIS, but the attackers were "home-grown" militants, from Europe.

Also found Tuesday, at a residence raided in Schaerbeek, were about 35 pounds of TATP explosives, about 40 gallons of acetone, 30 liters (about 10 gallons) of oxygenated water, detonators, a suitcase full of bolts and nails, and other materials used to make explosive devices.

The Islamic State of Iraq and Syria (ISIS) claimed responsibility for the attacks at Brussels Airport and one an hour later on one of the city's metro trains, near the station of Maelbeek. Most of the victims were killed in the train blast.