Racing Victoria chief handicapper Greg Carpenter announced the decision at 11.30 on Monday morning.

Fairfax Media reported exclusively on Sunday that the Caulfield Cup winner's owner, multi-millionaire Riichi Kondo, was threatening to pull the horse out of the race if he was given a penalty. It is yet to be seen if he will carry through with the threat.

Carpenter was hopeful Kondo would not withdraw Admire Rakti, but suggested he would understand if such a call was made.

"Whatever decision they make, I will be respectful of that. At the end of the day my decision making process is based around giving the horse a weight that I think that it can win with and being fair to the other horses that will run against it in the Cup," Carpenter said.

"If the owner decided that they would rather not run in the race and go back to Japan for the Japan Cup, I will be disappointed but I will be very respectful of that decision.

"I hope they take up the challenge to win the Melbourne Cup - the greatest 3200m race in the world."

Admire Rakti had already been allotted topweight of 58 kilograms in the Cup.

The nature of the penalty has been passed on to Kondo, who said via his interpreter that connections will take some time to digest the information before deciding whether Admire Rakti will take his place in the field.

Carpenter wanted the Admire Rakti camp to take its time.

"We will no doubt get some sort of commentary from Admire Rakti connections in the next 24 hours. Really there is no rush, the next round of deadline for acceptances is not until next week, so they don't have to make a decision straight away," Carpenter said.

"I think it's always best to let the dust settle and analyse race weights and decisions that are made so I would be hoping that they won't make a decision in the next 24 hours, I would hope that they would see how the horse pulled up, analyse the challenge that lies ahead, work out what an extra half a kilo means and then make a balanced decision - that I hope will be to take up the challenge."

Kondo had earlier expressed his concerns about the prospect of Admire Rakti being burdened with anything more than 58 kilograms.

"Extra weight would be a worry because I must have the horse's welfare to think of," Kondo said on Sunday.

"I would be worried and concerned if he was to get any more than 58 [kilograms] on Melbourne Cup day. Back in Japan 58 is the highest weight allotted to any horse, so if he gets above that I will be worried."

Kondo said the Melbourne Cup was not the only race available for Admire Rakti, including the Japan Cup on November 30. The stayer ran fourth in that race last year.

Carpenter had said the decision whether to penalise the Japanese stayer was the most difficult job he has had in a decade of assessing Melbourne Cup weights.

"He's got 58 already and when you get to these high echelons of weights you have to be careful not to overload the amount of kilos extra they carry," he said on Sunday.

"In theory over 3200 metres, every half a kilo is worth a length, so you've got to be very careful when reassessing a Caulfield Cup winner to a Melbourne Cup winner."

Not since Think Big in 1975 has a horse to carried 58.5kgs to victory in the Melbourne Cup. Since the introduction of the metric system in 1972, only Think Big and Makybe Diva (58kg, 2005) have carried more than 57kg to win the race.

Admire Rakti was hugely impressive at Caulfield, coming from midfield to mow down Rising Romance in the final 50 metres. His connections have maintained since being in Australia that he would be much better suited at Flemington.