Gregson, 25, has earned a spot in the men’s 1500m as part of the IAAF’s new roll-down policy, where vacancies are offered to the next-best placed athletes in the world rankings.

The NSW runner broke the longstanding Australian record with his time of three minutes 31.06 seconds set five years ago in Monaco.

Gregson has been in solid form so far this year.

The other additions to an Australian team which now numbers 45 are Heidi See in the women’s 1500m and James Nipperess, who was shocked to learn that a position had opened up in the 3000m steeplechase.

Further vacancies from the roll-down process meant Jeff Riseley was able to add the 1500m to his racing program, having previously qualified automatically in the 800m.

Relay runner Anneliese Rubie will also take a spot in the individual 400m.

‘‘It’s great to see our team shaping into one of the biggest we have taken to the world championships,’’ said Australian head coach Craig Hilliard.

‘‘There are a number of athletes not competing through injury that we would have expected, but the squad still includes 42 individual starters.

‘‘That’s a great result.’’

The world championships run from August 22-30 at the iconic Birds Nest stadium, the centrepiece of the 2008 Olympics. AAP