London ? Police said Friday they had begun an investigation after a woman oversaw the cremation of a body she believed was her son – who turned up alive the next day.

Greater Manchester Police said the mix-up began when the body of a man in his 30s was discovered in Manchester, northwest England, on Oct. 12. He was identified as Thomas Dennison, 39, by a care worker who knew him.

Officials contacted Dennison’s mother, Gina Partington, 58, who identified the dead man as her son. The body was released to the family and the funeral took place Tuesday.

The next day, Dennison was discovered alive in Nottingham, 80 miles away.

Partington said the resemblance between the dead man and her son was remarkable.

Police said they believed they knew the identity of the dead man, who had been living on the streets, and were trying to contact his relatives in Ireland.