Charlie Sheen's son in hospital

(BANG) -

Charlie Sheen's three-week-old son Max is still in hospital.

The 'Two And A Half Men' actor and his wife Brooke Mueller welcomed twin sons Bob and Max into the world on March 14 - but one of the boys has not been allowed to go home.

It has been reported the tot is suffering from a heart condition, but the 43-year-old actor insists the tiny baby is just underweight.

Charlie's publicist Stan Rosenfield said: "Charlie and Brooke's infant son remains in the hospital, not because of a heart condition as reported, but because he has not gained the weight necessary to leave.

"Max is expected to reach the weight requirement shortly and will join his brother Bob at home. The Sheens appreciate the outpouring of concern but have assured everyone that both Bob and Max are fine."

The twins were born prematurely last month when Brooke was rushed into hospital with early contractions.

But Charlie - who also has daughters Sam, five, and Lola, three, with ex-wife Denise Richards and 24-year-old daughter Cassandra from another marriage - insists Max is just a fussy eater.

He joked: "The weight issue is very common among infants who were born before reaching full term. I know a lot of people are not fond of hospital food - I just didn't realise they that started so young!"