Portland officials are threating legal action against the landlord of an apartment building where a fire in November killed six people, for safety violations at a building he owns on Dartmouth Street, a city spokesman said Thursday.

Gregory Nisbet has until Feb. 2 to bring 186-188 Dartmouth St. up to code, said spokeswoman Jessica Grondin.

While many properties in Portland have fire code violations that landlords are reluctant to address, Grondin said the city is taking swift action in this case because the building has problems similar to those that were found at 20-24 Noyes St.

Fire officials announced Wednesday that the fire Nov. 1 on Noyes Street was caused by an improperly disposed cigarette butt that ignited materials on the front porch, engulfing the front door in flames. Officials confirmed that they found no evidence of functioning smoke alarms in the building, and that a back exit was blocked, forcing the three survivors to jump out a second-story window.

At least four lawsuits have been filed against Nisbet on behalf of the victims. The full fire investigation, which is not yet public, has been forwarded to the district attorney for a determination of whether criminal charges are warranted, since the building appeared to have been operated as a rooming house.

“I think the circumstances surrounding the Noyes Street fire and what we’re finding here (at Dartmouth Street) is similar, so we need to take action in this manner,” Grondin said.

Nisbet’s attorney, David Chamberlain, has denied that the Dartmouth Street building was a rooming house, and said that the tenants were responsible for the violations, including locks on bedroom doors, extension cords running down hallways and stairways, damaged plumbing, a disabled heating system, illegal space heaters and piles of trash.

“Most of the violations were caused by tenants,” Chamberlain said after an eviction hearing on Jan. 8. “My client sought eviction to avoid further potential problems or dangerous circumstances.”

City inspectors first did a safety inspection of 188 Dartmouth St. on Dec. 15, after tenants complained that Nisbet was not responsive to their concerns about black mold, a lack of fire detectors and combustible materials stored near a furnace. The city tried to inspect 186 Dartmouth St. but the tenants wouldn’t allow them in.

Inspectors concluded that Nisbet was operating 188 Dartmouth St. as a rooming house, because tenants said they each negotiated their rent with Nisbet. Inspectors also saw padlocks on the outside of bedroom doors, which is a fire violation for an obstructed exit.

Rooming houses are required to have fire alarm systems with emergency strobes installed, rather than typical smoke detectors.

Electrical problems, the use of extension cords as permanent wiring, improper storage of combustible materials and excessive debris in the building were among the 10 violations cited.

Grondin said inspectors returned to the property in early January but the tenants, who were facing eviction for causing most of the damage, would not let them in.

The city received a warrant to inspect on Tuesday morning and conducted a follow-up inspection that day.

Grondin said some issues, such as the electrical problems, have been addressed, but the building still lacks a fire alarm system, locks remained on the outside of the bedroom doors, and the back exit was blocked.

The re-inspection also revealed that a smoke detector on the second-floor hallway was not functioning, Grondin said.

Grondin said the city finalizing its violation notice to send to Nisbet.