French police launched an investigation into how taped exchanges between police and a jihadist gunman who killed seven people in March came to be broadcast on national television on Sunday.

Interior Minister Manuel Valls condemned the decision to run extracts of the negotiations, recorded during a 32-hour siege at an apartment in Toulouse, southwest France, where police cornered Mohamed Merah in March.

Lawyers for relatives of the victims also denounced the broadcast of the recordings, while legal sources reported that the Paris prosecutor had opened an investigation into the leak of the tapes.

French station TF1 ran on its early evening news programme extracts from the exchanges, in which the 23-year-old Al-Qaeda-inspired gunman could be heard defying the police and declaring he was not afraid to die.

Merah, whose victims included three Jewish children, eventually died in a shootout as a crack police unit tried to storm his apartment.

"I know that there's a chance you could kill me, that's a risk I'm taking," said the gunman in the extracts broadcast by TF1.

"So there we are - know that you are up against a man who is not afraid of death."

Valls condemned the broadcast of the extracts in a statement issued shortly after the programme aired, regretting that it had come at a time when court proceedings relating to the killings were still ongoing.

It showed a lack of respect to relatives of the victims, he said a statement released by the interior ministry.

The police unit responsible for internal investigations, the IGPN, would be launching an investigation, the interior ministry said.

The producer of ‘Sept a Huit’, the programme that broadcast the extracts, defended decision to run the tapes.

"We acted responsibly," said Emmanuel Chain, saying the tapes' contents had a high news value.

"We learn how Merah trained with Al-Qaeda, his determination," Chain said. "We learn a lot of things, it has been very much put in context."

It was precisely because they had the feelings of relatives of the victims in mind that they had decided not to run other parts of the tape, he added.

But a lawyer for relatives of Imad Ibn Ziaten, the first soldier killed by Merah, said he had filed a complaint for violation of the secrecy of an investigation and receipt of stolen goods.

"The family is outraged, because these murders are not a show and the documents are part of judicial proceedings, said Mohan Mouhou, who represents the victim's parents.

Samia Maktouf, another lawyer representing relatives of those killed, said they would go to court to get an order banning any further broadcast of the tapes on any medium.

"The victims are outraged to learn the contents of these negotiations on television," she said.

"At this rate, the videos of the killings will end up on the Web and the damage then will be irreversible," she added.

Merah filmed his killings and in March the pan-Arab television channel al-Jazeera received a copy on a USB memory key at its Paris bureau.

The channel decided not to run the footage and the main French television networks also said they would not run the material if it became available.

A Frenchman of Algerian descent, Merah shocked France when he killed three soldiers and four Jewish people between March 11 and 19.

The case highlighted shortcomings in France's counter-terrorism operations, with authorities criticised for not taking Merah as a serious threat, even though they knew he'd gone to Pakistan and Afghanistan.