WINNIPEG -- Manitoba Premier Greg Selinger says he knew "early on" that one of his ministers had likely misled the legislature.

But Selinger says he didn't go public with the knowledge because he wanted to let the provincial ombudsman complete his investigation into Christine Melnick, and did not think the probe would take 18 months.

Selinger says the controversy was one factor in a cabinet shuffle that saw Melnick removed from cabinet in October.

The provincial ombudsman revealed last week that Melnick ordered a senior bureaucrat in April 2012 to invite immigrants and support workers to the legislature for a debate in which she criticized the federal government.

The finding contradicts what Melnick had told the legislature, and the ombudsman says the action created the perception of a partisan civil service.

Selinger says his government would be unlikely to organize a similar debate in the future, and has agreed to issue new guidelines to avoid the perception of partisan civil servants.