Police say they have booked many cases involving non-Finns who have been engaged in fraudulent fundraising activities, allegedly on behalf of the deaf community.
The tricksters have often tried to impersonate the hearing impaired as they try to persuade gullible pedestrians to part with their money.
One of the scammers was exposed when the target turned out to be an employee of the Finnish Association for the Deaf and immediately saw through the act.
Law enforcement officers say they uncovered the fundraising swindle last summer when about 80 cases were reported in different parts of the country, with the highest number occurring during the spring and summer months.
The perpetrators come mainly from Eastern Europe, predominantly Romania, according to police data.
The swindlers can often be found plying their trade in commercial parking lots and parking halls, mostly in the Helsinki area.
Police speculate that the fraudulent fundraising activity may be part of wider criminal operations and is likely to last for some time.
The Deaf Association said it fears that the activities of the fraudsters may cause the public to lose faith in legitimate fundraising programmes.