use strict;
use Data::Dumper;

my %hash;
while (<DATA>) {
    chomp;
    my ($key, $value) = split /\|/, $_;
    my @values = split /,/, $value;
    if (defined $hash{$key}) {
        push @{$hash{$key}}, \@values;
    }
    else {
        $hash{$key} = [\@values];
    }
}

print Dumper \%hash;

__DATA__
9344220001|sei10720013,21/07/2009-00-00-00,23/07/2009-12-34-44
9344220001|sei10720014,23/07/2009-20-00-23
9344220002|sei10720015,21/07/2009-00-00-00,23/07/2009-12-34-44
9344220003|sei10720016,23/07/2009-20-00-23
9344220003|sei10720017,23/07/2009-20-00-23
9344220003|sei10720018,23/07/2009-20-00-23