The takeover of Playtech could be derailed by Asian investors snapping up shares in the firm.
The gambling software specialist backed a 680p-a-share offer from Australian gaming group Aristocrat in October, valuing it at £2.1billion.
The deal was already under threat from rival suitor Eddie Jordan, the former Formula One motor racing boss understood to be mulling an offer worth around 750p a share, or £2.3billion.
Target: Gambling software specialist Playtech backed a 680p a share offer from Australian gaming group Aristocrat in October valuing it at £2.1bn
But attention is now turning to a group of investors from China and Hong Kong who have amassed stakes in Playtech, some of whom have paid more than the 680p offered by Aristocrat.
It includes billionaire heiress Karen Lo, Birmingham City Football Club owner Paul Suen and professional poker player Stanley Choi - as well as gaming tycoon Tang Hao and Hong Kong investment firm TTB Partners.
Holding: Billionaire heiress Karen Lo has been buying Playtech shares at around 750p each through her firm Future Capital Group
There is speculation they are part of a group that may control over 20 per cent of shares, potentially enough to block the takeover offer from Aristocrat, as over 75 per cent of investors need to vote in favour of the bid.
Sources said they were ‘mystified' by the intentions of the Asian investors.
It has been suggested they could be eyeing up Playtech's unregulated gambling business in the region.
Playtech and Aristocrat have written to the Takeover Panel and asked them to establish if these shareholders are acting together, according to Sky News.
If the panel says they are, the investors will fall under takeover rules stipulating they will have to make a full-blown offer for Playtech if their collective stake passes 30 per cent.
Lo, heiress to the Vitasoy Hong Kong soy milk empire, has been buying shares at around 750p via her firm Future Capital Group.
The 50-year-old, who is married to businessman Eugene Chuang and has a £75million mansion in Los Angeles, now has a 4.9 per cent stake.
In the race: Rival suitor Eddie Jordan (pictured), the former Formula One boss, is understood to be mulling an offer for http://google.com Playtech worth around 750p a share or £2.3bn
Suen, a Chinese businessman, has expanded his stake to just over 4.6 per cent.
Choi, a businessman and professional poker player, is chairman of hotel and casino property investor International Entertainment Corp.
He has a 3 per cent stake in Playtech, and is better known in the UK for his controversial tenure at Wigan Athletic FC, which he owned for 20 months and sold shortly before it fell into administration last year.
Concerns over a potential blocking of the deal followed a decision by Gopher Investments, a firm linked to TTB, to pull out of a possible counter-bid for Playtech last month.
Gopher made an approach for the whole company after it triumphed in a battle to buy Playtech's financial trading arm, Finalto, for £189million in September.
Risk taker: Professional poker player Stanley Choi is among the group of investors from China and Hong Kong who have amassed stakes in Playtech
Meanwhile, Eddie Jordan and his firm JKO Play are thought to be putting together a potential 750p per share offer that it is hoped will be recommended by Playtech's board.
Aristocrat's offer stipulates that any commitments to vote for its bid will lapse if a rival proposal is at least 10 per cent higher.
This means any counter-offer will need to be at least 748p.
JKO has until January 5 to make a formal offer.
Playtech is considered by some to be a hidden gem in the UK's gambling sector, with giants including William Hill and Bet 365 among its customer base.