TORONTO -- Toronto police have issued a warrant for a Philippine man on a first-degree murder charge in the death of a 78-year-old widow.

Investigators say they believe Fernando De Castro, 46, fled Canada along with his wife in late November and that they are now back in the Philippines.

It's alleged that De Castro and his wife Melpa De Castro, arrived in Canada in 2007 as visitors and that they worked as house cleaners.

Police say the victim, Manijeh Bostani-Khamsi, hired the couple to clean her home and became well-known to them.

She was found dead in her apartment in the Wynford Drive and Eglinton Avenue East area on Nov. 17 and police have said she was murdered the previous day following an altercation.

Police allege that Fernando De Castro was in the woman's apartment some time around 11:50 a.m. on the day she was killed and that he and his wife fled the country on Nov. 20.

Anyone who had contact with De Castro during the early-afternoon hours of Nov. 16 or has any knowledge of his whereabouts around that time is asked to call police.