Speaking from Sydney Airport, Riichi Kondo said he was "concerned" by the penalty of half a kilogram but had decided to allow the horse to start in the Cup. He said the seven-year-old entire would have been sent back to Japan if the penalty had been any higher.

On Monday morning, Kondo requested a full list of weights for previous Melbourne Cup winners and the penalties Caulfield Cup winners had received over the past 30 years. Kondo then met with advisers during the day and, as he left for Japan late on Monday, said the horse could start.

On Sunday, Kondo said any penalty would be a "major concern" and believed that getting to 58 kilos would test the horse.

Kondo, one of the most powerful owners in Japan – his building firm employs more than 3000 – has about 100 horses in work and has been a driving force behind change in racing there in the past 20 years.

With Admire Rakti a confirmed starter, punters returned to the international as their choice in the Cup. Bookmakers said money started to come for German stayer Protectionist when there was a shadow over the Caulfield Cup winner starting, but that trend had reversed since late Monday. Admire Rakti is a top-priced $6.20 with Betfair.

It is also understood that those staff members based in Australia were extremely keen for the Caulfield Cup winner to attempt the famous double. Admire Rakti had pulled up well and the staff overseeing the stayer were delighted with the horse's progress since Saturday.

"I'm so pleased that they have decided to stay, I've had talks with them and they've discussed the situation fully and decided to run," recruiting scout Leigh Jordon said.

"Mr Kondo had made it clear that anything above 58 kilos was a worrying amount of weight to carry, but I think, as all Australian racegoers would say, we're so pleased he's staying and running in the Cup," Jordan said.

The Tomoyuki Umeda-trained stayer has been penalised for his stylish victory in Saturday's Caulfield Cup (2400 metres) – the first by a Japanese horse.

Racing Victoria general manager of racing, Greg Carpenter, said the visitor could not escape penalty despite already being topweight.

"While the Caulfield Cup was not run in fast time, Admire Rakti was enormously impressive making a long, sustained run down the middle of the track and he was strong through the line at the end of 2400m suggesting that 3200m at Flemington would be to his liking," Carpenter said.

"In making a decision on whether to penalise the horse in the Melbourne Cup for his maiden group 1 triumph I had to strike a balance between the terms on which those that finished behind him at Caulfield would meet him next start and the new wave of rivals that awaits him at Flemington.

"Internationals Red Cadeaux, Cavalryman, Willing Foe, Protectionist, Mutual Regard and Royal Diamond, and potentially Cox Plate runners like Fawkner and Silent Achiever, present a new challenge for Admire Rakti and this had to be considered when determining the penalty.

"I have penalised Admire Rakti 0.5kg for his win thus lifting the original topweight to 58.5kg in the Melbourne Cup. This is the lowest penalty given to the Caulfield Cup winner since Ming Dynasty escaped one in 1980, but this is tempered by the fact that since the Melbourne Cup went metric in 1972 only Think Big (58.5kg) in 1975 has carried more than 58kg to victory."