In 2009 he received a letter from the SIS director Warren Tucker, who neither confirmed nor denied that the SIS had any information on Mr Karpichkov.
When asked if he was paranoid or a bit crazy, Mr Karpichkov said: "Other people from my profession are paranoid as well. Everything I am talking about could seem like paranoia, but unfortunately it's happened."
Mr Karpichkov was a Russian spy in Latvia, but in 1995 began passing information to the Latvian Government and its Western allies.
When he was discovered in 1998, he fled to London, but became frustrated after eight years of being mucked around by immigration authorities.
In June 2006, when an agent told him his life could be in danger if he stayed in the UK, Mr Karpichkov flew to Auckland on a forged Lithuanian passport.
"It was expensive. I got it through British-based Russian organised crime.
"I tried to find work [in Auckland] but it was impossible. Who will employ a person whose immigration status is uncertain?"
He is currently suing the British secret service, the MI5, for invasion of privacy, harassment and unlawful surveillance - something he says the SIS did to him in Auckland.
"I have been quite thoroughly trained to notice if I'm under surveillance," Mr Karpichkov said. "I didn't pay too much attention until my health began to be affected."
In Auckland's Queen St in November 2006, a person who looked like a "common beggar" attacked him and tried to steal his laptop while throwing a dust-like substance at him.
In the months that followed, he lost more than 20kg and his body hair started falling out. He now believes he was poisoned.
"I was quite a fat man, and what happened to me within two or three months I still can't figure out."
He kept a database of documents and pictures, including of several cars that visited him often but were all registered to fake addresses.
He had hoped to gain refugee status and then bring his wife and two children to New Zealand, but his application was initially declined. He appealed to the Refugee Status Appeals Authority, but it was still being considered when he flew back to the UK - on the same forged Lithuanian passport.
"I left because my health became too bad. Basically, I thought I was going to die."
Now a British citizen, his health has since stabilised.