As above use a match stick or the skewers you can buy for roasting marshmallows or bbq sticks which are a bit thicker.and a wood glue, clean out the hole, cut a short length of skewer to fit the hole depth, glue the hole and push in the skewer piece,.you can wait till it sets but try it as is and don't overtighten the screw until the glue has set.
Thanks for you help, I had used match sticks in the past, but without glue,
So, what I ended up doing was, drilling out the holes with a 4mm drill bit, twisting it gently with my fingers. Then cutting some white plastic plugs and glueing them with epoxy resin .
Left them overnight. Worked a treat.