Women's Boat Race umpire Sir Matthew Pinsent has explained why the Oxford crew wasn't disqualified despite an apparent breach of the rules. Just two minutes in, the race was halted after the Oxford boat drifted into the path of its rivals.

The oars clashed on the River Thames, and a disqualification seemed on the cards. However, rather than award Cambridge the win, they were instead given a third-of-a-length advantage when the race restarted. It mattered little as they went on to retain their title, but pundits still questioned the decision.

Pinsent, a four-time Olympic gold medalist, explained: "Obviously there was a clash between the crews that stopped the race. To my mind I was clearly warning Oxford in the run-up to that.

"At that moment, when you have got two crews at a standstill, there is no way they were going to carry on racing. The clash was heavy enough that it was going to stop the race."

Pinsent admitted that a outright disqualification was considered. However, he also argued his call was justified amid the fact that it didn't adversely affect the final result.

"There are a range of options at that moment. You could DQ someone straight away, you could restart," he added. "That disqualification pops into your mind but you can also allow, after a restart, to see if it affected the outcome of the race. Obviously in my opinion it did not affect the outcome of that race and that's what's going on in my head now."

This year's event had already been plagued by controversy. Today's scheduled trial race was cancelled due to an eligibility row, while Olympic champion Tom Hill was also banned from competing for Oxford.

There has also been safety fears over the condition of the river in the Thames. Routine testing carried out along the four-mile route revealed E coli levels three times above the threshold for poor bathing water status, prompting London mayor Sadiq Khan to defend the hosting of the event.