The parents of a missing student want the provincial government to hold an inquest into their son's disappearance, which occurred while he was tree planting in a remote area of northern Ontario.

Aju Iroaga, a 26-year-old engineering student at McMaster University, was last seen waiting by the roadside for a bus on May 15, 2006, after quitting his summer tree planting job about 70 kilometres north of White River, Ont.

He left following a dispute with a supervisor.

The parent's lawyer, Marlys Edwardh, said the police investigation didn't provide any answers. The Ontario Provincial Police never interviewed any of the other tree planters, but they believe Iroaga never walked out of the bush and is likely dead, though no foul play is suspected, she said.

Iroaga's parents, who are still grieving, were at Queen's Park on Monday morning, urging government officials for a coroner's inquest and a probe by the Ministry of Labour to shed light on many unanswered questions about their son's disappearance.

Such a request is currently under review, but a decision could take months, Edwardh said.

Opposition parties said the Labour Ministry has an obligation to investigate the case because it raises serious questions about the safety of workplaces in remote regions.

With files from the Canadian Press