Great Britain's 13-year reign as Olympic men's team pursuit champions came to an end on a day of drama, intrigue and a snap retirement at the Izu velodrome.

It began with three-time Olympic champion Ed Clancy abruptly calling time on his career through injury, continued with allegations that world champions Denmark were cheating and then – in a first round clash with those same Danes – ended with a bizarre crash between Frederik Madsen and Charlie Tanfield.

The best Britain can hope for now in the event is seventh place, but the arguments will surely go on.

Denmark's kit first came under scrutiny on Monday, when they were seen with all four riders sporting medical tape on their shins – an apparent breach of UCI regulations stating riders cannot wear anything that does not constitute the tightly-controlled clothing.

Performance director Stephen Park confirmed Britain had been one of "several" teams to call for the Danes to be disqualified, having set their opening time while wearing both the controversial tape and undervests which had not been properly registered.

At a lively meeting of teams before Tuesday's session, the UCI confirmed the equipment could not be used again but indicated there would be no retroactive punishment despite rules saying a team should face elimination in such circumstances.

"There was a fairly heated debate about whether the UCI were or were not going to apply their own rules about (the tape) and about undervests," Park said.

The argument threatened to turn petty. All equipment used must have been commercially available since January 1. Though the Danish undervest is for sale and appears to have been so for some time, Park claimed others had discovered the source code of the relevant website had recently been changed.

"The information relating to the kit being available on January 1 was only added in the last 24 hours," he said.

Park left open the possibility of further appeals, but by the end of the day it would make little difference to Britain.

Tanfield was rushed into action as a late substitute for Clancy. For all the millions spent and the years of preparation for this day, Britain went into their first round clash with a rider who had spent two and a half hours of Monday riding his road bike, no thought apparently given to this scenario.

It was therefore little surprise to see Tanfield struggle to keep up once Britain were reduced to three. That said, it clearly shocked Madsen, who was in his aero tuck and did not realise he had caught Tanfield until he rode into his back wheel and both men hit the deck.

The UCI deliberated for 30 minutes over what happened next.

Britain's men's endurance coach Iain Dyer argued a precedent was set at the Nations Cup in St Petersburg last month, where Swiss rider Claudio Imhof rode into Davide Plebani in an individual pursuit and was disqualified for causing a crash.

But instead the UCI declared that Denmark had won the race by catching Britain's last rider – rules state a pursuit is over once a team gets within one metre of their opponents, a measure seemingly met if they collide.

It was all a deeply unsatisfactory way for Britain to hand over their crown, but debates over the rules seem like a distraction given their best time was five seconds off the new world record set by Italy later in the day.

Dyer insisted Monday's qualifying time – though almost three seconds better than any previous British ride in competition – was still well short of their best in practice, but that too was academic in the end.

"We would have been right at the sharp end for sure," Dyer said. "But that's just ifs and buts. You've got to deliver on the day."