An MTA effort to get paratransit riders to use subways and buses more often by giving them free MetroCards lacked oversight that led to fraud, according to a report from an agency watchdog.

The report from the MTA inspector general said the MTA was randomly giving Zero-Fare MetroCards to those who qualify to use Access-A-Ride. The program is supposed to save the MTA $90 million a year by 2015 by getting paratransit riders on subways and buses and off the costly paratransit service.

But the report detailed abuse of the program by looking at the 10,338 MetroCards used at least once between September 2013 and February, out of the nearly 31,000 cards sent out last year.

For the 612 cards given to riders who need a free fare for a personal assistant, 10% of the cards were swiped excessively.

"These excessive trips are almost certainly fraudulent," the report said.

There was also a "significant amount of fraudulent use" of cards sent to the 750 riders in wheelchairs; more than 40% of cards issued to them were swiped 9,222 times at nonaccessible stations, according to the IG.

The MTA defended the cost-savings from the free MetroCard program while agreeing with recommendations, such as deactivating unused or abused cards, notifying riders the cards will be monitored for fraud and put an oversight system in place.

"Access-a-Ride cost-cutting measures enacted over the past couple of years have resulted in millions in savings," an MTA spokesman said in a statement. "We will reinvest a portion of these savings into a fraud prevention/detection unit and are already in the process of developing and implementing fraud controls."