However, the spokesman did not specify whether it was a flight data recorder or a cockpit voice recorder of the nearly new Boeing 737 Max 8 jet plane that crashed into the waters of Tanjung Karawang shortly after taking off from Soekarno-Hatta airport.
The devices record information about the speed, altitude and direction of the plane as well as flight crew conversations.
Search teams on Wednesday detected signals possibly from a black box of the crashed Indonesian Lion Air plane, a rescue official said.
It is too early to determine what led to the disaster, the carrier's owner Rusdi Kirana has said.
The accident is the first to be reported involving the widely sold Boeing 737 MAX, an updated, more fuel-efficient version of the manufacturer's single-aisle jet.
The aircraft, a brand new Boeing 737 Max, was flying erratically on Monday morning as well.
The Lion Air plane with 189 people onboard crashed into the waters off karawang of Indonesia's West Java province shortly after taking off from Jakarta on Monday.
A passenger on the fatal Lion Air Flight 610 shared a video of himself and other passengers boarding the plane.
"We could see a lot of passengers' belongings - lifejackets, pants, clothes - underwater not just on the surface", he added, saying the debris suggested the main fuselage should be nearby.
"We have also intensified (on-site) checks on Lion Air, starting today", Budi said, referring to monitoring of the airline's airmen, operator and the company itself to ensure that they are conducting flights safely and in compliance with regulations.More news: Nadal pulls out of Paris Masters with abdominal pain
Lion Air flight JT-610 disappeared just 13 minutes after it took off from Indonesia's capital Jakarta, bound for an island a little more than an hour away.
Although the seafloor is only about 30 metres down, strong currents and energy pipelines in the area have hampered search efforts.
Lion Air, Indonesia's biggest budget airline which has been engaged in huge expansion, announced earlier this year it was buying 50 Boeing-737 MAX 10 jets for $6.24 billion.
Daniel Putut, a Lion Air managing director, said the airline and Boeing will meet Wednesday afternoon.
National Transportation Safety Committee investigator Ony Soeryo Wibowo addressed media in Jakarta following the discovery, explaining that the particular piece of equipment was not recovered in its entirety.
The disaster has reignited concerns about safety in Indonesia's fast-growing aviation industry, which was recently removed from European Union and USA blacklists, and also raised doubts about the safety of Boeing's new generation 737 MAX 8 plane.
"Some passengers began to panic and vomit".
Searchers have sent 57 body bags containing human remains to police identification experts who on Wednesday said they had identified their first victim, a 24-year-old woman, from a ring and a right hand.
Lion Air, a low-priced carrier, was barred from flying in US or European Union airspace due to its poor safety record.