Just add a check if contactLinesForPage allready contains this contact. Something like this:
for(Contact c : searchResults) {
Boolean toInsert = true;
for(ContactWrapper cw : contactLinesForPage){
if(cw.contact.Id == c.Id){
toInsert=false;
}
}
if(toInsert){
contactLinesForPage.add(new ContactWrapper(contactLinesForPage.size(), c, ''));
}
}