The mystery surrounding St George Illawarra Dragons' forward Hame Sele's time in hospital continues to deepen, with reports he has been diagnosed with a serious heart condition.

Sele was taken to hospital on Saturday evening during the Dragons' disappointing loss at home against the Canterbury Bulldogs at a sold out Kogarah.

It was reported at time that Sele was suffering from an 'irregular heartbeat' as well as difficulty breathing.

Sele took to Instagram on Monday morning to reveal him being in hospital was 'precautionary' while the Dragons also released a statement confirming Sele had been battling the flu in the weeks leading up to the game against Canterbury and was in hospital for that reason, making specific mention of the fact Sele did not suffer an irregular heartbeat.

Despite that, News Corp are now reporting that the forward has been diagnosed with pericardial effusion.

This is a serious heart condition that can be deadly if left untreated, although in some cases, the patient wouldn't even realise there is a problem.

The condition however can be caused by a virus.

โ€œPericardial effusion can be caused by a virus and associated with other medical and viral diseases. It's a complex problem to resolve, find its potential cause and manage," a doctor is reported to have told the publication.

It's understood Sele consulted cardiologists on Monday afternoon to run further testing on the forward, and there is now no timeline on when he will be out of hospital, although he has been transferred out of the emergency ward.

It's reported that, either way, Sele's season is over with no chance the 27-year-old will be back on the park in the next month as his Dragons' teammates fight for a place in the finals, likely needing two wins from the final four games of the campaign to qualify.