Anna Elisabet Eberstein and Hugh Grant in 2011
01/30/2014 AT 09:30 AM EST
Hugh Grant is a father again – and in fact, this boy is more than a year old already!
The actor, 53, had a son in 2012 with Swedish TV announcer Anna Elisabet Eberstein, according to the Sun
newspaper. The two have reportedly been seeing each other for two years.
The news was only revealed when Grant's full name, Hugh John Mungo Grant, was printed on the child's birth certificate when the birth was re-registered in December.
The space was reportedly left blank on the first birth certificate.
The boy, whose name has not been made public, was born three months before the birth of Grant's second child, Felix Chang,
with former girlfriend Tinglan Hong.
Grant and Hong, 33, also have a daughter, Tabitha Xaio Xi
, born in September 2011 in London. It is not clear if Hong was aware of Grant's simultaneous affair with Eberstein. A source told the Sun
, "They were pregnant with Hugh's children at the same time. It's an unusual arrangement."
A rep for Grant did not return calls.
Susanne Eberstein, Anna's mother, said in an email to the tabloid Aftonbladet
this week: "It is a wonderful little cute grandchild boy i have got. I already had a grandchild since earlier, and it's such fun to have another one."