David Sullivan has told Birmingham's new owners to concentrate on strengthening the squad.

Carson Yeung's Grandtop International completed their takeover last month, with the deal rubber-stamped by the Stock Exchange on Wednesday.

However, there have been reports of friction with the old regime as Yeung is understood to be unhappy with the pay-off given to Karren Brady.

Grandtop have also discovered there were around £6million worth of unpaid bills but Sullivan insists they have no right to hold a grudge.

Former co-owner Sullivan hopes Yeung will invest heavily in the January transfer window and bring in several new players.

"I'm livid, flabbergasted. We left a well-run football club. They seem to have a vendetta against us," Sullivan told The Sun.

"You have to question what their motives are. We are told that they are going to spend £40m in January and they should be looking forward to that.

"Maybe they are now having a few doubts about spending it and see this as a possible excuse.

"We are fed up with all these stupid statements. They should get on with running their football club."

Sullivan, cleared in August after a two-year investigation into allegations of conspiracy to defraud and false accounting, is furious that Grandtop are pursuing such matters.

"If they want to waste police time it's up to them but we have nothing to hide," he said.

"If Grandtop International haven't done proper due diligence that's up to them. This is sour grapes.

"Name me somebody who has bought a Premier League club and not found unpaid bills.

"There is always money owed on players.

"Then to hear talk about the fraud squad. I've never heard such a load of rubbish in my life."