PORTLAND, Maine — Back Bay Tower, a 16-story luxury apartment building at 401 Cumberland Ave., has a waiting list of prospective tenants.

But the building seems to be attracting something much less desirable these days.

In the past few months, residents and staff have been finding “significantly” more used syringes and other drug paraphernalia on the grounds, property administrator Amy Winn said Monday.

“Before, it used to be we’d find [a syringe] maybe a couple times a week. Now it’s seven days a week, and we’re finding multiple syringes.” In addition, she said more “aggressive” people are hanging out near the building.

The situation will be discussed by Bayside’s neighborhood watch group at its next meeting, 6 p.m Tuesday, Oct. 8, at Back Bay Tower.

The problem of illicit drug use near the tower was dramatized last month when children from the building found an unconscious man near their school bus stop with a hypodermic needle in his arm, Winn said. The stop, at Cumberland Avenue and Mechanic Street, has since been moved to the building’s front entrance.

Police did not immediately respond to attempts to get more information about the apparent rise in drug activity near the tower but are aware of the problem, according to Winn.

“I think the community policing has been stepped up, and [the officers] are doing the best they can,” she said. “But the problem is overwhelming.”

Steve Hirshon, Bayside Neighborhood Association president, said the problem has been an “ongoing” one for the area. But he said he believes the use of intravenous drugs such as heroin may be growing in the neighborhood as users switch from prescription painkillers like oxycodone, which are increasingly difficult and expensive to obtain.

“This is something the neighborhood’s lived with,” he said. “What’s going on now isn’t really a matter of a surge [in drug use], it’s a matter of the drug of choice. People are turning to injectables.”

Other evidence may support Hirshon’s theory.

Earlier this year, city officials reported that heroin use in Portland had “increased dramatically.”

In May, emergency personnel responded to five overdoses — including one death — during a single 24-hour period.

In July, the epidemic of heroin use in Portland made the headlines of The New York Times. The paper reported that northern New England was regarded as a “wide-open market” for the drug, where a bag of heroin selling for $6 in New York can fetch $30 or $40.

Hirshon noted that Back Bay Tower could be seeing an increase in the syringes because the large building and its grounds may be difficult to monitor, providing secluded areas where users can shoot up.

That’s one of the reasons Winn has stepped up safety measures recently. She has hired two private security officers and installed additional outdoor lighting. And she’s excited that a proposed 57-unit affordable housing development at 409 Cumberland Ave. may bring more people to the area.

“We think [the development] is a great complement to us, and it may deter some of this behavior since there will be more people around,” she said.

If the problem continues, Winn said she worries that Back Bay Tower residents may move elsewhere. She said she believes the building has already lost a few long-term residents for that reason.

“This has to be addressed. Bayside is an up-and-coming place, and I love being in this neighborhood,” said Winn, who besides managing the building has lived in it for 22 years. “The majority of residents here don’t want to think about going anywhere else.”