The Opera House Hotel in the South Bronx has been confirmed as the source of New York City's deadliest-ever Legionnaires' disease outbreak following laboratory testing, city Health Commissioner Dr. Mary Bassett said Thursday.

Bassett also announced the incubation period has ended and "the outbreak is over."

The boutique hotel and former theater's cooling tower had a strain of bacteria with the same "DNA fingerprint" as 25 samples from patients, some of whom have died, Bassett and Deputy Health Commissioner Dr. Jay Varma said at a news conference at the city's public health laboratory in Kips Bay.

The samples were tested by city, state and federal laboratories, Bassett said.

The hotel in a statement Thursday called the news "obviously disappointing," but noted that city and state health officials have demonstrated professionalism and kept them informed in the past 10 days.

"Tests completed just yesterday [Wednesday] confirm that our tank is completely clear of any Legionella pneumophila," the hotel said.

The hotel was one of five sites that originally tested positive for the Legionella bacteria in the flare-up that killed 12 people and sickened 116 others in the South Bronx.

City and state "disease detectives" tested 30 cooling towers in the area and found 14 positive in the affected area, Bassett said.

Last week, an executive representing the Opera House Hotel criticized city officials as "reckless" for leaking half-baked information" speculating on its role in the outbreak.

Legionnaires' disease is a noncontagious form of pneumonia.

No one has reported the onset of symptoms since Aug. 3.

Mayor Bill de Blasio on Tuesday signed into law a mandate that buildings with cooling towers be registered and cleaned and tested regularly.