Brussels (AFP) - Belgian police have found a Brussels flat where bombs used in the Paris attacks could have been made and where key suspect Salah Abdeslam might have hidden after the massacre, prosecutors said Friday.

One of Abdeslam's fingerprints, three hand-made belts for possible use in suicide attacks and traces of explosives were discovered during a search in December of the apartment in the Schaerbeek area, they said.

The flat was rented by someone using a false name, possibly used by another suspect in the November 13 Paris attacks who is now in custody in Belgium, the federal prosecutor said.

Prosecutors said Abdeslam might have hidden in the flat after the November 13 attacks, but that they were also working on the theory that the explosive devices used in the massacre could have been made there.

"We found the fingerprint but we have no idea when it was left -- a fingerprint has no date or time on it," prosecutors' spokesman Eric Van Der Sypt told AFP.

"Maybe he went there to get his belt (before the attacks), and maybe he went back afterwards. I suppose it's a possibility of both," he added.

- Explosive traces, vests found -

An international manhunt has been underway for Belgian-born Abdeslam, 26, since suicide bombers and assailants firing automatic weapons killed 130 people and wounded many more in a wave of attacks across Paris.

Investigators said friends drove Abdeslam from Paris back to the Belgian capital, slipping through three police checks, while one suspect has since said that he drove Abdeslam across Brussels to Schaerbeek on November 14.

Prosecutors said the raid was carried out "in the framework of the investigation opened after the Paris attacks". They did not explain why details were only being released a month after the search.

"During a house search conducted December 10th in an apartment on the third floor, Rue Berge in Schaerbeek, material that can be used to fabricate explosives as well as traces of TATP were found," the prosecutor said in a statement, referring to a type of explosive.

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"This apartment was rented under a false identity that might have been used by a person already in custody in this case," the statement added.

"Three handmade belts that might be used to transport explosives as well as a fingerprint of Salah Abdeslam were also discovered."

One source close to the investigation told AFP that it "is my personal opinion that the explosive belts used by the attackers from Belgium were made in the apartment" in Schaerbeek.

- Hunt continues -

After the attacks, French authorities said that telephone data had placed Abdeslam in the area where an explosives belt was found in a dustbin in the Paris suburb of Montrouge.

The Islamic State group claimed responsibility for the coordinated series of attacks on bars, restaurants, and a concert hall, in which the attackers were armed with guns and suicide belts. Seven died during the assault but the total number of those directly involved is still unclear.

One of them was Abdeslam's brother, Brahim.

In early December, Belgian prosecutors said they were looking for two "armed and dangerous" men who used false ID papers to help Abdeslam travel to Hungary in September where he was stopped -- but then let go -- by police.

Belgian authorities have arrested and charged a total of 10 people in connection with the attacks, including several with helping Abdeslam.

France has long said the attacks were prepared and organised in Belgium and that the mastermind was Abdelhamid Abaaoud, a Brussels resident who was killed in a police raid in Paris days after the massacre.

But the source close to the investigation told "there's still a lot of work to do" to put the puzzle of the attacks together. "That's the million dollar question," he added.

He said investigators still did not know "where the weapons came from, and who coordinated the attacks."

Nor do they know where the ingredients for "the home-made explosives" were bought or what operational links the attackers had with the Islamic State group.