Ottawa police say their investigation began in December 2013 after a third-party complaint about alleged illegal labour.
Investigators found a 26-year-old woman entered the country legally as a domestic worker for a Filipino couple as a nanny.
But they also found the couple, a 45-year-old man and a 44-year-old woman, exploited the victim for “financial and material benefit” from July 2009 to December 2013 at their home.
At the time, the accused, Bueneflor Cruz and Robert Cruz, had diplomatic immunity.
On April 30, police requested a waiver of immunity from the Department of Foreign Affairs, Trade and Development Canada (DFATD) to proceed with criminal charges.
Police said Bueneflor Cruz had been on posting with the Embassy of the Republic of the Philippines and Robert had joined her in Ottawa.
But on Monday, DFATD informed police the couple had surrendered their identity cards and returned to the Philippines.
A Canada-wide warrant was then issued for the couple’s arrest.
The husband and wife have been charged with trafficking a person by exercising control, trafficking a person for financial/material benefit and withholding or destroying identification documents for the purpose of facilitating an offence.
Robert Cruz was also charged with uttering threats to cause bodily harm and mischief under $5,000.
The victim remains in Canada in a safe location, police added.