Wendy Houvenaghel has launched a bitter attack on British Cycling, claiming she was "shabbily" treated and denied a gold medal.
The 37-year-old admitted to being aggrieved at being left out of the team pursuit, describing the decision as "vindictive".
Houvenaghel, from Northern Ireland, was omitted from the Olympic team pursuit squad of Joanna Rowsell, Southampton -born Dani King and Laura Trott which won gold at the weekend.
Despite a run of world records for the trio, Houvenaghel claims she was promised a place in the squad for the Track Cycling World Championships in Melbourne and the Olympics due to her strong training performances.
Qualified dentist Houvenaghel won individual pursuit silver behind Rebecca Romero in 2008, but committed to the team event when the track programme for London 2012 was radically altered.
It was the three-time world champion's one chance at Olympic gold to cap a cycling career which began at the age of 31.
But it turned to disappointment when British Cycling head coach Shane Sutton told her she would not be riding even though, Houvenaghel claims, Rowsell was struggling with illness hours earlier.
Rowsell began the second round, effectively a semi-final, because the team had already been declared, but Houvenaghel was told to get ready for the final, only to then be informed she would not be riding.
Houvenaghel told Press Association Sport: "I feel particularly aggrieved that the head coach made the decision to put in a rider who wasn't 100% well on the start line twice.
"Thankfully the girls did go on to win their race but perhaps had I been allowed to do my job that world record could have been faster.
"We had done faster times in training in Newport the week before with me in the line-up.
"I do feel I have been deliberately omitted from that opportunity that was mine and the opportunity to bring home a gold medal to Northern Ireland.
"The last gold we had was 40 years ago with Dame Mary Peters. It's a very shocking and upsetting decision."
Houvenaghel wished her team-mates luck, left the velodrome and moved out of the athletes' village and has only had contact with British Cycling's sports psychiatrist Dr Steve Peters and the squad's logistics manager in the two days since.
Had Houvenaghel ridden in one of the three rounds, she would have had her medal.
She added: "I've been treated really shabbily by an organisation which I have been dedicated to for six years, have won many medals for and have been a key member of the team pursuit team.
"To not allow me to ride in a three-minute race, which I can do with my eyes closed, practically, and let me pick up my Olympic gold medal was just vindictive and something which is going to take a lot of getting over."
British Cycling declined the opportunity to comment.