The 18-year-old boy told reporters that he carried out the act after consulting a spiritualist, who promised to make him rich.
The suspect, with other suspected criminals arrested by the police in Edo, were paraded today in Benin by the Commissioner of Police (CP) Johnson Kokumo.
According to the police, the suspect confessed to strangling his mother at 5 a.m. on October 10 in Ologbo, near Benin, while the woman was asleep.
He said that he had sexual intercourse with her corpse for two days as instructed by the spiritualist.
The suspect disclosed that luck ran out on him as he was arrested when his grandmother, who became suspicious of him, raised an alarm.
The police also arrested two suspected cult members for gang-raping a girl being initiated into their group.
Kokumo said that a 21-year-old man from Bayelsa State was also arrested for robbing a woman of N1, 450.
Kokumo told reporters that 88 suspected criminals were arrested in different parts of the state in the past three weeks.
He said that among the suspects was a 21-year-old man from Ogun, who was the leader of a car-snatching syndicate that had been snatching cars in Benin metropolis.
Kokumo thanked members of the public for supporting the command and solicited more assistance to enable the police to make the state safe.
He added that the suspects would be arraigned as soon as investigations were completed.