Russian fighter jets fired a missile near an unarmed British RAF plane over international waters, the Defence Secretary told the Commons on Thursday.
Ben Wallace called the incident over the Black Sea on September 29 was “potentially dangerous”.
He said the Kremlin had acknowleged the missile firing and claimed its aircraft had a “technical malfunction”.
The Government initially suspended patrols over the Black Sea in response, but they have now resumed with the RAF planes escorted by fighter jets.
Mr Wallace said the unarmed RC-135W Rivet Joint, a British spy plane, was patrolling and when it was shadowed by the Russian SU 27.
He told MPs: “It is not unusual for aircraft to be shadowed. During that interaction, however, it transpired that one of the SU 27 aircraft released a missile in the vicinity of the RAF Rivet Joint beyond visual range.
“The total time of the interaction between the Russian aircraft and the Rivet Joint was approximately 90 minutes...In light of this potentially dangerous engagement. I've communicated my concerns directly to my Russian counterpart.”
He added: "In my letter I made clear the aircraft was unarmed, in international airspace, and following a pre-notified flight path.
"I felt it was prudent to suspend these patrols until a response was received by the Russian state.
"The reply by the Russian minister of defence on October 10 stated they have conducted an investigation into the circumstances of the incident and stated it was a technical malfunction of the SU-27 fighter.
"They also acknowledge that the incident took place in international airspace."
Labour’s Shadow Defence Minister Luke Pollard described the incident as “serious”, and welcomed the fact that RAF flights have restarted.
“The RAF have this House’s full support and we are grateful to them, to other UK forces, and our Nato allies in their work protecting the alliance and protecting freedom,” he said.
“This incident also acts as a serious reminder about the importance of avoiding escalation and miscalculation while continuing the UK’s united support for Ukraine.”
He added: “Putin needs to be in no doubt that our resolve will continue and, whether it’s (Mr Wallace‘s) party or my party that’s in charge, that will not change.”