The remains of a man who was killed in the Sept. 11 terrorist attacks on the World Trade Center have been positively identified, the New York City medical examiner’s office announced on Monday, amid continuing efforts to return victims’ remains to their loved ones.

The man, whose name was withheld by officials at his family’s request, was the first Sept. 11 victim to be identified in more than two years.

Recent improvements to how DNA is extracted and tested helped confirm the man’s identity late last month after years of negative results, the medical examiner’s office said Monday. He was the 1,641st person to be positively identified of the 2,753 people killed when the twin towers were destroyed.

Dr. Barbara Sampson, the city’s chief medical examiner, said forensic scientists had continued to test the remains as more advanced methods had become available. The vast majority of named victims were identified using DNA or a combination of techniques, according to city data. Positive identification of the remains, which are mostly bone fragments, allows victims’ families to finally claim what is left of their loved ones.