The Russian double agent fighting for his life after a suspected nerve agent attack had ties to spymasters from the country he betrayed, it has been claimed.
Fellow Russian exile Valery Morozov said he met Sergei Skripal several times, but alleges the former colonel had not left his life in espionage behind.
Mr Skripal was convicted in his home country for selling secrets to the British.
He was freed in an exchange of captured spies between the US and Russia in 2010.
Mr Morozov told Channel 4 News that, despite his high-profile defection, the poisoned intelligence officer visited the Russian Embassy regularly.
He said: "If you have a military intelligence officer working in the Russian diplomatic service, living after retirement in the UK, working in cyber-security and every month going to the embassy to meet military intelligence officers - for me being political refugee, it is either a certain danger or, frankly speaking, I thought that this contact might not be very good for me because it can bring some questions from British officials.
"What is the meaning (of being a) political refugee if I have a contact? Rather strange, especially with cyber-security, because cyber-security and his background, they look very strange for me, let us put it like this.
"So that's why I thought it's better not to call him. It will be better to be aside."
The Russian Embassy denied any such contacts between Mr Skripal and its staff.
It told the broadcaster that the critically ill father was not on "the consular register".
Mr Morozov claimed to have detailed knowledge of the Kremlin's inner workings and expressed doubt that Vladimir Putin orchestrated the assassination attempt.
Before fleeing the country he worked in the Kremlin's analytical service and then in the main organ of information warfare.
He said: "The main rule there is you should not create problem for (the) Kremlin. That's how I survived personally.
"For Putin, it is very important not to create scandal around him, to keep (the) situation calm. I can't imagine that somebody has given this task.
"Who is Skripal? He is nobody for Putin, absolutely. Some man who officially betrayed the country. That's all. He's nobody. Putin doesn't think about him. There is nobody in Kremlin who is thinking about former military intelligence officer who was nobody. What is the reason?"
Mr Skripal, 66, remains in hospital with his daughter, 33-year-old Yulia, after the pair were found slumped on a bench in Salisbury last weekend.