He was aged 59.
Effiom passed away on Tuesday in hospital after suffering a stroke, according to his wife.
Cross River State Sports Commissioner, Patrick Ugbe, also confirmed the death, saying “I was informed that he took ill a day after the Nigeria match against Congo in Calabar and was taken to hospital, where he died.”
“He was a great inspiration, a good man who believed in me,” two-time African women footballer of the year Cynthia Uwak told BBC Sport.
“I’m still in shock, I can’t put words together but I pray he finds rest in the bosom of The Lord.”
Uwak, who made the shortlist for the 2006 Fifa World Player of the Year award and came in 11th in the final votes’ tally, says the death of Effiom is a great loss.
“He was one of the top coaches in Nigeria who worked passionately in women’s football,” Uwak added.
Effiom coached Cross River State-based club Pelican Stars to multiple Nigerian league and Cup titles before being appointed to take charge of Nigeria’s U-19 Women’s side at the World Championship in Canada in 2002.
Two years later he was promoted to coach of the Super Falcons and he went on to lead them at the 2007 World Cup in China.
Effiom retired from the civil service in September 2013.