Passing escaped semicolon as a matrix parameter value

The requirement is to pass a value containing ';' character (escaped as '%3B') into @MatrixParam managed variable.

For example:
I have a request like this:

http://server/r=value1%3Bvalue2

and a matrix parameter:
@MatrixParam( "r" )
private String parameter;

what I receive is a value of the 'parameter' variable equal to 'value1' and I expect it to be 'value1;value2'