David Lytton's body was discovered at Dove Stone Reservoir in Greater Manchester on 12 December 2015.
He was born David Lautenberg on 21 April 1948 but his name changes to Lytton on the electoral register in 1987.
The 67-year-old flew into London Heathrow from Lahore, Pakistan, two days before his body was found.
He was identified from photos from a passenger list and picked up on CCTV in London.
Greater Manchester Police (GMP) said his identity was confirmed as a result of a DNA match with a relative.
The electoral register examined by BBC Newsnight showed David Lautenberg was listed as living at 46 Lilian Road, London, SW16 5HN from 1982 to 1986, while David Lytton was listed there from 1987 onwards.
It is understood he changed his name due to a family feud, the Guardian reported.
Mr Lytton, who had lived in Pakistan for 10 years, was found fully clothed, lying prone on the ground above the reservoir.
He had no wallet, phone or other identification and remained unidentified despite numerous public appeals and the release of CCTV footage of his last known movements.
In June 2016, the BBC investigated the mystery of the unidentified body.
Why did this man travel 200 miles to die on Saddleworth Moor?
Police said a "provisional" cause of death had been determined as "strychnine poisoning". Police believe he took his own life.
An international police investigation was launched after a post-mortem examination revealed he had a type of titanium plate in his leg which was only manufactured and fitted in Pakistan.
Greater Manchester Police and the National Crime Agency contacted the medical community and the British Embassy in Pakistan to appeal for information.
DNA analysis confirmed that he was David Lytton from London, who had "no obvious connection" to Saddleworth.
Mystery still surrounds the case and why he chose to head to Greater Manchester after returning from Pakistan.
A full inquest is due to take place on 14 March.
A mystery man who was found dead on Saddleworth Moor had previously changed his name.