Justicia for Migrant Workers, an advocacy group, says dozens of migrant workers who did not match the identity of a suspect were asked to submit to DNA tests. Police say the investigation led to an arrest. (Canadian Press)

A group that advocates for the rights of migrant workers alleges the Ontario Provincial Police engaged in racial profiling when its officers took DNA samples from about 100 Caribbean migrant workers.

Justicia for Migrant Workers submitted a complaint to Office of the Independent Police Review Director on Thursday.

In October, an alleged sexual assault occurred, reportedly by a migrant worker, in Vienna, Ont., near Tillsonburg.

Police asked dozens of migrant workers for DNA samples, but not from people who matched the specific suspect description, the advocacy group claims.

The group's spokesman, Chris Ramsaroop, said the suspect was originally described as a black male in his mid to late 20s, 5-11 and muscular.

Ramsaroop said police then tested males between 21 and 61 years old, standing between five feet and 6-5 and weighing between 130 and 310 pounds.

"From talking to the workers, the only characteristic that they decided to do and engage in the volunteer — quote, unquote volunteer — sweep was around racial characteristics," Ramsaroop said.

Lenard Sylvester was one of the workers who voluntarily gave a DNA sample. He thought it was odd for the police to ask him, considering he was much shorter than the suspect police were seeking.

"To me it felt strange, knowing that they had they had a total description of who they're looking for. Colour, height, probably a little bit of the language, too," said the native of Trinidad. "And still they were having everybody doing the DNA testing and requesting it and all that. And they made it look like a show of force."

Police stand by their investigative tactics in the case.

Last week, senior officers announced that DNA evidence had helped lead to the arrest of a migrant worker in the area.

"Criminals know no boundaries and our message today is very clear to them — neither do police," Insp. Dwight Peer said.

Sgt. Dave Rektor denied there was any racial profiling. He said investigators followed the evidence within the parameters of the law.

"We're confident in the investigative results and we stand by our investigation," Rektor said. "In this case here, it was a thorough and complete investigation and we stand behind that."

According to Ramsaroop, workers say they fear unjust prosecution in a foreign land.

Ramsaroop is also concerned about what happens to DNA samples that were not a match to the accused.

Rektor said those are destroyed by the centre of forensic science.

Sylvester said he'll be returning to work again from Trinidad next year, but his views of the police have changed.

"They'll have to show me down the road, probably next year or some time, that they're different," said Sylvester.