Efforts to retrieve the recorder will begin during the day, the official added, quoted by AFP news agency.
Meanwhile doctors say the only survivor of the crash, teenage girl Baya Bakari, is recovering and in no danger.
The plane, flying from the Yemeni capital Sanaa to the Comoros, came down in bad weather with 153 on board.
There were 66 French nationals among the passengers. Most of the rest were Comorans.
Most of the passengers had flown on a different Yemenia aircraft from Paris or Marseille before boarding flight IY626 in Sanaa.
"The black box's signal was located yesterday [Tuesday] at 1630 local time (1230 GMT) by an aerial patrol, 40 km [25 miles] from Grande Comore," a spokeswoman for Co-operation Minister Alain Joyandet said.
Most aircraft have a flight data recorder and a cockpit voice recorder. It was not clear which of the two from the Yemeni plane had been located.
'Still hope'
A French vessel has been sent to the site to start recovery operations, she added. French rescue teams are already involved in the search for survivors.
She's a very timid girl, I never thought she would escape like that
Father of survivor Baya Bakari
Apart from the 14-year-old girl found alive, no-one from the plane has been confirmed alive, and rescuers say chances of finding more survivors are slim.
AFP news agency quoted hospital sources in the Comoros capital Moroni as saying they were preparing to receive another child survivor, but Mr Joyandet later said no more survivors had been found.
Sources close to the Comoran rescue team say the only confirmed survivor, who has been named as Baya Bakari, was being treated in Moroni and her condition had improved.
The Associated Press news agency quoted her father as saying she had been travelling with her mother to the Comoros from Paris to visit family.
Kassim Bakari said she had been ejected from the plane when it came down and clung to debris for several hours until she was rescued.
"She's a very timid girl, I never thought she would escape like that," he said, describing her as "fragile" and barely able to swim.
He added that he was mourning the loss of his wife whilst overjoyed at his daughter's extraordinary escape.
Doctors at the hospital said she had cuts to her face and a fractured collarbone, but was not in danger.
"She is very calm given the shock she suffered," surgeon Ben Imani told Reuters.
Angry protest
Meanwhile doctors say the only survivor of the crash, teenage girl Baya Bakari, is recovering and in no danger.
The plane, flying from the Yemeni capital Sanaa to the Comoros, came down in bad weather with 153 on board.
There were 66 French nationals among the passengers. Most of the rest were Comorans.
Most of the passengers had flown on a different Yemenia aircraft from Paris or Marseille before boarding flight IY626 in Sanaa.
"The black box's signal was located yesterday [Tuesday] at 1630 local time (1230 GMT) by an aerial patrol, 40 km [25 miles] from Grande Comore," a spokeswoman for Co-operation Minister Alain Joyandet said.
Most aircraft have a flight data recorder and a cockpit voice recorder. It was not clear which of the two from the Yemeni plane had been located.
'Still hope'
A French vessel has been sent to the site to start recovery operations, she added. French rescue teams are already involved in the search for survivors.
She's a very timid girl, I never thought she would escape like that
Father of survivor Baya Bakari
Apart from the 14-year-old girl found alive, no-one from the plane has been confirmed alive, and rescuers say chances of finding more survivors are slim.
AFP news agency quoted hospital sources in the Comoros capital Moroni as saying they were preparing to receive another child survivor, but Mr Joyandet later said no more survivors had been found.
Sources close to the Comoran rescue team say the only confirmed survivor, who has been named as Baya Bakari, was being treated in Moroni and her condition had improved.
The Associated Press news agency quoted her father as saying she had been travelling with her mother to the Comoros from Paris to visit family.
Kassim Bakari said she had been ejected from the plane when it came down and clung to debris for several hours until she was rescued.
"She's a very timid girl, I never thought she would escape like that," he said, describing her as "fragile" and barely able to swim.
He added that he was mourning the loss of his wife whilst overjoyed at his daughter's extraordinary escape.
Doctors at the hospital said she had cuts to her face and a fractured collarbone, but was not in danger.
"She is very calm given the shock she suffered," surgeon Ben Imani told Reuters.
Angry protest
The French transport ministry had earlier said the Airbus 310 plane which crashed had been banned from France because of "irregularities".
But Yemenia responded by criticising "false information and speculation about technical problems" on the plane.
Several Comoran expatriates angry with what they see as the poor state of the company's aircraft tried to stop passengers from checking in for another Yemenia flight leaving Paris Charles de Gaulle airport for Sanaa.
About 60 people failed to check in, reports said, but it was not clear how many did so as a result of the protest.
The crash was the second involving an Airbus aircraft in recent weeks. On 1 June an Air France Airbus 330 travelling from Rio de Janeiro to Paris plunged into the Atlantic, killing all 228 people on board.
HOW THE BLACK BOX WORKS
Flight data recorders, or "black boxes", are in fact orange or red.
Commercial aircraft carry two. One logs performance and condition of aircraft in flight, another records conversations of crew and their contact with Air Traffic controllers during the flight.
The Crash Survivable Memory Unit (CSMU) contains a memory board surrounded by thermal insulation and steel armour that can withstand a crash impact thousands of times the force of gravity and survive in the sea at depths of 20,000ft (6,096m).
The CSMU is insulated to sustain temperatures up to 1,100C for up to an hour or "low" temperature fires of around 260C for 10 hours.
An underwater locator beacon fitted on recorders emits continuous ultrasonic "ping" when they come into contact with water. The signal can reach the surface from depths of 14,000ft.
But Yemenia responded by criticising "false information and speculation about technical problems" on the plane.
Several Comoran expatriates angry with what they see as the poor state of the company's aircraft tried to stop passengers from checking in for another Yemenia flight leaving Paris Charles de Gaulle airport for Sanaa.
About 60 people failed to check in, reports said, but it was not clear how many did so as a result of the protest.
The crash was the second involving an Airbus aircraft in recent weeks. On 1 June an Air France Airbus 330 travelling from Rio de Janeiro to Paris plunged into the Atlantic, killing all 228 people on board.
HOW THE BLACK BOX WORKS
Flight data recorders, or "black boxes", are in fact orange or red.
Commercial aircraft carry two. One logs performance and condition of aircraft in flight, another records conversations of crew and their contact with Air Traffic controllers during the flight.
The Crash Survivable Memory Unit (CSMU) contains a memory board surrounded by thermal insulation and steel armour that can withstand a crash impact thousands of times the force of gravity and survive in the sea at depths of 20,000ft (6,096m).
The CSMU is insulated to sustain temperatures up to 1,100C for up to an hour or "low" temperature fires of around 260C for 10 hours.
An underwater locator beacon fitted on recorders emits continuous ultrasonic "ping" when they come into contact with water. The signal can reach the surface from depths of 14,000ft.