LOS ANGELES, Feb 28, 2024 (BSS/AFP) - The blistering 44.49sec 400m indoor time set by Canadian teenager Christopher Morales Williams last weekend will not be ratified as a world record due to an issue with the starting blocks, US officials said on Tuesday.

The United States Track and Field and Cross Country Coaches Association (USTFCCCA) made the announcement in a post on X, formerly Twitter.

Although describing Morales Williams' run as an "all-time world best", the USTFCCCA said the teenager's time won't count as an official world record because of the starting blocks used in the race at a collegiate meeting in Arkansas on Saturday.

The 19-year-old University of Georgia student blasted to victory ahead of JeVaughn Powell (45.61) and Chris Robinson in 45.62 in Saturday's race.

Initially, Morales Williams' time was believed to have broken the previous world mark, but the world record will remain the 44.52 set by American sprinter Michael Norman in March 2018.

Reports in the US on Tuesday said the starting blocks used in the race did not comply with World Athletics regulations governing the ratification of world records.

According to the rulebook, blocks must be linked to a World Athletics "start information system" which monitors reaction times.

The USTFCCCA post said Morales Williams had been drug tested after the competition "so that wasn't an issue."