Trainer Liam Birchley has confirmed recent Doomben winner Underneaththeradar has been sold to Hong Kong and warns others will follow if prize money in Brisbane is not raised.

Underneaththeradar won his only Brisbane start when he landed a $12 to $4 plunge on May 28 at Doomben.

Birchley was immediately contacted by Hong Kong interests who made a "substantial offer" for the Hidden Dragon three-year-old who cost $26,000 as a yearling.

"He passed the vet last week so he is off to Hong Kong," Birchley said.

"You can't blame connections with the way prize money is in Queensland at the moment."

"It is still hard to win a race here but you would have to win a dozen of them to match what Hong Kong is offering.

"Of course they aren't the only centre looking at buying good tried horses."

"Until something is done about the prize money levels things won't be any different."

Underneaththeradar is the second smart maiden winner Birchley has lost from his stables in the past four months.

King Halo, who scored barnstorming win at Doomben in February, will also do his future racing in Hong Kong.

In the past six months at least 10 promising Queensland horses have been sold to Hong Kong including potential Group horse Flight King, winner of three Gold Coast races.